-cas 4th jumpstart

7/26/2019 -CaS 4th Jumpstart

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Command at Sea 1

Command at Sea - Jumpstart

Fourth Edition

An Introduction to the Command at Sea System


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Command at Sea 2

Introduction This Jumpstart guide is designed to show you how to play Command at Sea in as short a time as possi-ble. It includes a rules summary, a sample scenario and the rules necessary for playing the battle. The chartsand tables needed to play the game are not included here, so you cannot play a game without the full rulesset. You can, however, read this summary and then play, using the full rules as a reference. These rules are extracts from the fourth edition rules booklet. Most of the explanation, and all of the illus-trations, sidebars, and optional rules have been removed. They are repeated in the full rules set. You do notneed this booklet to play the full game. This battle concentrates on the movement, visibility, gunnery, torpedo, and damage rules. Although thegame could be simpli ed by ignoring visibility, it was such an important part of WW II at sea that playingbattles without it produces unrealistic results.

Rules Summary If you are familiar with wargaming, you can probably get most what you need from this one-page sum-mary and use the rules booklet as a reference. Wargamers are an impatient lot. Tactical Turns are three minutes long, with movement and re simultaneous and plotted in advance. Athirty-minute non-combat Intermediate Turn is provided for long movements. Plotting is followed by movement, then planned re, detection, and reaction re phases. Reaction reallows players to re at targets detected that turn, with reduced effectiveness. The phases are performedsimultaneously by both players. Gunnery attacks against surface targets have a xed chance to hit with modi ers based on the rangeband: Short, Medium, Long (normal effective range), and Extreme. One roll is made for each attack. Thedamage per mount is xed, and is affected by range. Armor penetration is xed and is based on range. Ships have a belt and deck rating, which is comparedwith the penetration ability of the shell. If it is greater than the rating, then the shell penetrates. Non-penetrat-ing hits halve their damage. Anti-aircraft re is abstracted, with two values: An Area AA strength for 75 mm and larger calibers and aLight AA strength for 65mm and smaller. Area AA re can be used any time an aircraft is within range, andto defend other ships. Light AA can only be used against planes directly attacking that ship or passing within2,000 yards. For both types, a single die roll is made for each ring ship, and the result shows how manyaircraft are shot down. Surface ship and submarine torpedo attacks are made by a using table to nd the correct lead angle, thenring the torpedoes along that line, marking the spot of launch. Torpedoes move at their rated speed alongtheir course line until they are within 500 yards (optional: exible danger zone depending on the run length).Players roll on hit tables based on the apparent size of the target, the length of the torpedo run, and the num-ber of weapons in the spread. Aerial torpedo attacks are based on the number dropped and modi ers. A single die roll then gives thenumber of torpedoes hitting the target ship. Dive bombing attacks are made in the same way, with the numberof bombs dropped and a die roll indexed to nd the number that actually hit. Planes can also strafe ships, butwith limited effectiveness. Air-to-air combat is abstracted, with all dog ghts occurring inside an imaginary circle. Within that circle, anaircrafts exact position is unde ned. Players compare aircraft Maneuver Ratings to nd out who attacks rst.The attacking player chooses an opponent, compares his Maneuver Rating with the targets, then rolls dice to

see if he gets in position to re. Aircraft speed and pilot experience are both important modi ers. The attack-ers gun attack ratings are then matched against the targets damage rating and a die roll to see if the target isshot down. There are rules for formation ight. Maneuver Ratings are also used in determining an aircrafts climbing abilities. Rules are provided for night combat, including searchlights, aircraft ares, starshells, and radar. Ships can attack submerged subs with depth charges or ahead-thrown weapons. Unless the ship is ttedwith a depth- nding sonar (rare in WW II), the attacking player must estimate the subs depth. The effective-ness of individual depth charges is combined into a single pattern, with a single die roll for its effect. Ships canlay different types and sizes of patterns, depending on how many depth charge launchers/rails they carry. Planes can attack subs with rockets, depth charges and homing torpedoes; rolling percentile dice to see ifthey hit.


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What has Changed in the Fourth Edition Its been ten years since the third edition of Command at Sea , and countless games have raised just asmany questions. Rules questions generate clari cations, corrections or expansions, and ten years of thosewould be reason enough for a new edition. Weve also harmonized the three games in the Admiralty Trilogy , unifying annexes, damage scales,formats, and making rules consistent in all three systems. Units listed in Harpoon or FG&DN can now be usedin CaS without change. Sensors work the same way in all three games, as do weapons. Many changes, likea new formula for damage points, are transparent to the players, but others, like adding a signature the shiplistings, require new rules. Weve also folded in the game expansions that have been published: The land attack and coast defenserules that rst appeared in No Sailor But a Fool , and the small craft rules that were published in MightyMidgets , and the mine warfare rules from Baltic Arena . First, read a rules section before using it. There are many small changes besides the major onesdiscussed here. For example, weve changed the rules for submarine battery endurance to better account forthe German late-war Type XXI and XXIII subs, Until youve actually read a section of the rules, dont assumeits the same as the earlier edition. The turn sequence is the same, except that there is no longer a second air movement phase. The rulesfor air attacks on surface targets and dog ghting have been simpli ed, so that the second air phase is nolonger necessary.

The movement rules are unchanged except for minor re nements. The altitude levels have changedslightly, and VLow and NOE are no longer separate altitude levels. They are de ned as special ight modesin the Low altitude band. Impulse movement has been added, a simpli ed version of what was rst publishedin Mighty Midgets . Visual detection now incorporates the rules from Mighty Midgets . There are now two types of modi ersto visual detection. Some change the visibility table that the players use, based on the physical sightingconditions, others change the chance of detection on a table. The variation is now a percentage of the basevisibility distance, rather than a xed number of yards. Radar now includes rules for clutter, which can be caused by land, nearby weather, or jamming. Byrating and comparing the different effects before a scenario starts, players can nd out which is dominant andhow effective their radars will be. Sonar has been simpli ed, as well as uni ed with the more complex systems in Harpoon . The threedetection bands are based on a 75% detection chance at half listed range, 50% at listed range, and 25% at

one and a half times the listed range. Modi ers for active and passive sonars have been changed, and likeradar clutter, some environmental modi ers will reduce detection range. Gunnery still uses the four range bands and a D100. The biggest change the players will see is that thereare two sets of modi ers, one for Gunnery Standards (GS) 3 and 4, and the other for GS 4m (small caliberweapons). The modi ers work differently: The player totals them up and then multiplies them by a percentage:4% for short and medium and 2% at long and extreme ranges. This allows the modi ers to have greater effectclose in. Air combat has seen the greatest changes. A new dog ght system uses the old Maneuver Ratings, but issimpler and takes into account both the energy of the aircraft and pilot experience. Initiative is determined byManeuver Rating and maximum speed. There are three (count them) ways of resolving aircraft damage. Air attacks on surface targets and AA re are also simpli ed, with planes now declaring their attacks at adistance from the target, then moving directly to their targets in three-minute steps. Defending players get thesame number of AA shots as before. Critical hits are now rolled with a D20, which allows more detail on the critical hit table. A new system forres and ooding models the capacity of the ships damage control teams, and what happens when they areoverwhelmed. The bridge and rudder criticals have nally been decon icted, and the effects of almost everycritical have been re ned. Check the l isted effects before applying them. Small craft are now an integral part of the game, and rules for their movement, detection, gunnery, anddamage can be found in the appropriate chapters. They are similar to the rules in Mighty Midgets , but notexactly the same. The mine rules in Chapter Ten allow players to design a mine eld, either as a referee before the game, oras a player attempting to lay one as part of a scenario. As always, we are ready to answer any question you have about the rules, new or old.


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WEAPONS DATA LINE EXAMPLES

Rules ExtractsChapter Two- Game Mechanics 2.2 Preparing for Play. After choosing a scenar-io, the players need one completed Ship ReferenceSheet for each ship and one completed Air DataCard for each aircraft or group of aircraft. Permissionis granted to photocopy the master Ship ReferenceSheet and Air Data Card for use in playing CaS . 2.2.1 Weapons . Each weapons line in AnnexA shows the weapons ring arc, number of barrels/ rails/tubes per mount, the number of mounts on theship, the weapon name, the ammunition availableper mount, and any weapon director present. TheWeapon Data Line Examples shows this format andhelps decipher this information. If more than one mount is present, the mountsare equally split between the available arcs. Similarly,if more than one director is present, they are splitbetween the available arcs. Some weapons do not have ring arcs. Someare catapults or aircraft, that do not require an arc.Others have a prede ned arc, and cannot pivot. Thisincludes such things as depth charges, which arerolled off a ships stern. These will be discussed inthe rules for their use. 2.2.2 Weapon Firing Arcs. Most weaponmounts have an arc of re. A weapon mounted for-ward cannot re directly aft because part of the shipsstructure blocks its re. Some weapons may not be

able to pivot, and the arc is limited by the weaponsability to turn after launch. The arc which can be usedby each weapon mount is shown in the ship listingin Annex A. If a target is not within the ring arc of aweapon, that weapon will not be able to re at thattarget. Some weapons can re into more than one arc:a gun mount may be able to re into both the PortQuarter and the Port Arc; its ring arc is expressedby combining the appropriate abbreviations with anampersand (in this case, P&PQ). A stroke (/) splits the arcs of multiple mounts: P/ S(1)2 indicates that there are two mounts, one ringinto the Port Arc and one into the Starboard Arc. Theparentheses refer to the number of tubes each mounthas. 2.3.1 Turn Concept . All play in CaS is simul-taneous. Both players plot their actions, reveal their

orders, move their vessels, and re their weapons atthe same time. Each Turn is divided into phases. These orga-nize the turn into periods when speci c actions maybe taken. Turns should be recorded in units of real time.For example, if the rst Tactical Turn is 0115, thenext would be 0118 then 0121, and so on. 2.3.4 Tactical Turn Sequence. The followingsequence of phases is executed by the players eachTactical Turn. Plotting Phase . Players write down (plot) move-ment, ring, and other orders for their forces. Players

may plan re for the coming Planned Fire Phase onlyagainst targets detected in the previous turns Detec-tion Phase. Movement Phase . Surface ships, submarines,and torpedoes move a distance equal to three min-utes of travel. Aircraft launches and landings takeplace. Torpedoes and missiles that reach their targetin this phase have a chance to hit their target andhave their attacks resolved immediately. Planned Fire Phase . All weapons ordered tore in the Plotting Phase are red simultaneously.Gun re and attacks by aircraft are resolved immedi-ately during this phase. Ahead-thrown ASW weaponsand depth charge attacks made in this phase areresolved immediately. Detection Phase . Players attempt to detectother units. A unit can react only to detected threats,even though the controlling player may be aware ofothers on the game board. Reaction Fire Phase . Shipboard guns andantisubmarine weapons which have not been usedso far this turn may now re at any target, includingones just detected. Torpedoes may not be red inthis phase. Aircraft re as before. Gun re and attacks

Annex with data on the weapon

P&S(5)3 533mm TT w/5 Type 93 F

Number of rounds carried per mount, ve Type 93 torpedoes. Weapon name. Number of mounts the ship carries. Number of tubes per mount - ve in this case, or quintuple mounts. Weapon arc. The three mounts have a combined port and starboard ring arc, meaning that all three mounts can re to either side.

Annex with data on the weapon

F/A(2)6 Mk32 5 inch/38//1 FD C

Radar director type (if tted) Weapon Name Number of mounts the ship carries Number of tubes per mount - Two in this case, or twin mounts Weapon Arc. The six mounts are split evenly between the forward and after ring arcs


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by aircraft are resolved immediately. Guns red inthe Reaction Fire Phase in ict half normal damage.Urgent depth charge attacks made in this phase areresolved immediately. Ahead-thrown ASW weaponattacks may not be made in the Reaction Fire Phase. Resolution Phase . Damage points caused byre and ooding critical hits are in icted in this phasethree Tactical Turns after the critical hit occurs. 2.4 Ship Size Classes. Many rules are based onthe size of the ships involved. This includes maneu-vering, detection and damage. To simplify things,ships are grouped into size classes. The rules willrefer to either a letter (e.g., Size Class A) or a de-scription (e.g., Large, Small). The classes are:

Naval Unit Size Class Table Size Size Class Displacement Description A 18001+ Large B 5501- 18000 Medium C 1501 - 5500 Small D 351 - 1500 Small E 86 - 350 VSmall F 21- 85 VSmall G 20 VSmall

2.5 Target Aspect . Gun and Torpedo re de-pend on the apparent aspect of the target. A bow-onbattleship is a smaller target than a destroyer broad-side to an observer. Using the target aspect diagram (page 2-6),players can determine whether they have a broad,quarter, or narrow aspect on the target.

2.6 Plotting Movement Orders. Since the play-ers move simultaneously, movement must be plot-ted ahead of time. For surface ships, players recordcourse and speed, which cannot be changed duringthe turn. Any increase or decrease in speed shouldbe checked against the ships acceleration/decelera-tion ability (section 3.1.1). If the player wants theship to steer evasively (section 3.1.5), he applies themodi er to gure out the ships nal speed over thewater. Direction and course changes can be written inany clear, consistent manner. It may be in terms of

a destination (Head for Lunga Point) or be basedon another ships movements (Close on enemybattleship, turn to parallel its course at 1,500 yards.)Remember to keep it simple and focus on the goal ofthe movement, not the process itself. 2.6.2 Torpedo Movement. Torpedoes movein each Movement Phase starting the Tactical Turnafter they are red. Torpedoes are moved like anyother units, however, the ring player can invokeproportional movement if it looks like the torpedo hasa chance of hitting (see sections 3.0.1 and 6.3.1).

If torpedoes are red, or it is expected thattorpedoes will be used in a game, the players shouldplot their moves one Tactical Turn in advance (thecurrent and one more). If new units are detected, ora ship suffers damage, the affected player can alterhis movement plot at that time, writing a new set oforders for that Tactical Turn and the next one.

Chapter Three - Ship Movement 3.1 Ship Movement. Ships, including subma-rines, have a maximum speed listed in Annex A. Thisis reduced by damage received in combat. Shipsmay move at any speed up to the maximum speedavailable to them. As it accumulates damage, a ships speed isautomatically reduced. Each 25% of its maximumdamage reduces its speed by 25%, until it reaches90% damage, when its speed is zero (it is dead inthe water). The break points for each damage percentageare included in each ships listing in Annex A. 3.1.1 Speed Change. Players order speedchanges in the Plotting Phase of a Tactical or Inter-mediate Turn. The amount of acceleration or decel-eration is limited by the type of ship, and for accelera-tion, its starting speed must also be considered. A ship can move from a dead stop to high speedquickly, but as speed increases, so does water resis-tance (its a square function) and the rate of accelera-tion is less. Acceleration rates are listed in the ShipAcceleration/Deceleration Table (page 3-2). Thereare separate tables for warships and merchants.There are no special rules for submarines.

Speed changes ordered in a Tactical Turn hap-pen immediately. For example, if a Fast A-sized shipat 20 knots is ordered to increase speed to 30, itsacceleration of 6 knots means that it will move at aspeed of 26 knots in the upcoming Movement Phase. 3.1.4 Course Changes and Turning. Shipsneed a minimum distance to turn. Called advance, itis the distance the ship moves in the original directionas the rudder bites and the ship changes direction.Large ships need more space than small ones. In most cases, such as maneuvering in open wa-ter, advance distances will not be an issue. At othertimes, such as at slow speed or in restricted waters,

the exact amount needed will be very important. The Ship Turning Distance Table (page 3-2) liststhe advance for each ship by size class for both aStandard and Hard rudder. Merchants are less ma-neuverable than warships, and have their own table.Most turns are made with Standard rudder, but inemergency situations a player can order Hard rudder,putting it over to the stops. There is a 5% risk of therudder jamming (5 or less on a D100). If it does jam,treat it as a critical hit (Jammed, roll for direction, seeRudder in 8.3). The ship continues to circle in that


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direction with the rudder hard over until the critical hitis xed. Unless otherwise plotted, all turns are assumedto use Standard rudder. To turn, rst move the ship the required distance,based on its size class and the rudder used, thenpivot it in place up to 45. A turn greater than 45must be made in steps of 45 or less. There is noreduction in the distance required for a turn of lessthan 45, except that adjustments of 10 or less perturn do not need to be accounted for. Even if a ship has moved in a straight line forseveral turns, the player must still move it the re-quired advance in a straight line before changingcourse. Advance is the distance the ship movesalong its original course line after the rudder is putover. If a player knows ahead of time that he will turnin a particular spot, and there is suf cient maneuver-ing room, he can order the turn ahead of time, andthe ship can turn at the start of its next MovementPhase. Ships also lose speed when they turn, becauseof the drag of the rudder and hull. The speed lostper 45 turn is shown on the Turn Distance Table. Inmost cases, the ships acceleration per turn automati-cally cancels speed lost from a single turn, but it maynot be enough if the ship is moving slowly or makesseveral course changes in one turn. The Ship Acceleration Deceleration Rate Tableshows how much a ship can accelerate in one three-minute Turn. For example, a Size Class C destroyer,moving at 35 knots, makes two 45 turns with stan-dard rudder. This causes a speed loss of 2 knots,

while it can accelerate 3 knots at the same time. Thenormal acceleration of 6 knots is halved because thedestroyer turned. Each 45 course change a shipmakes in a Movement Phase incurs a speed loss, upto the fourth change. After that, there is no additionalspeed loss. If the total speed loss from the ships turns in aTactical Turn exceeds the acceleration for the ship inthe same turn, reduce its speed for the present turnby the difference. 3.1.5 Evasive Steering. Ships can steer irregularcourses, or chase salvoes. By turning toward theshell splashes from the last enemy salvo, a ship can

throw off the enemys gun re corrections. It isnt fool-proof, but it helps. Of course, the rapid, unexpectedturns throw off the maneuvering ships gunners aswell (except for light weapons, 65mm or less), andships steering evasively cannot re torpedoes. A ship that wants to maneuver evasively plots itand declares it at the start of the Movement Phase.The ship is actually moving at its ordered speed, butcovers only 75% of the distance it normally would. A ship must move at 20 knots or more to steerevasively. Only ships of size class B or smaller can

steer evasively. Ships with rudder or bridge criticalhits cannot use evasive steering. Evasive steering modi es the gun re hit chancefor both the target and the shooter. The modi ers arelisted with the gun re hit chance modi ers, in section6.1 Surface Gunnery.

3.3 Torpedo Movement. Torpedoes are red inthe Planned Fire Phase, after movement for the turnis completed. When red, place two counters nextto the ring ship. One marks the torpedoes startingposition, the other is for the torpedo salvo itself. Thetorpedo salvo marker is not moved until the followingMovement Phase. On one side of the torpedo salvo counter, put aletter or symbol showing that it is a torpedo salvo andits speed. On the other, put the number of weaponsand the type. In the turns following the launch, the torpedoesmove in a straight line in a direction chosen by thering player (within ring arc limits). 3.3.1 Speed. Some torpedoes have two or morespeeds listed in Annex F. Slower speeds give thetorpedo a longer range. Any speed can be chosenat the time of launch. It cannot be changed once thetorpedo is launched. 3.3.2 Course Changes . An unguided torpedocan make one course change to anywhere within thering arc of its mount. Torpedoes were tted with gy-ros which were set before launch, and surface shipshad trainable tubes. Once on course it will not turn. 3.3.4 Range. The maximum range for each tor-pedo is provided in Annex F. If the torpedo reaches

maximum range without hitting anything, it runs out offuel and stops. It does not explode. Minimum arming range for all torpedoes is 250yards (1/8 nm). If one strikes a target inside that dis-tance, it has not had time to arm and will not explode.

Chapter Five - Detection 5.2 Radars . Radars use pulses of electromag-netic or radio waves to detect and track objects.Objects in their the pulses path re ect some of theenergy back to the antenna, where the direction ofthe re ection gives the bearing, and the time theecho takes to travel to the target and back gives the

range. 5.2.1 Radar Speci cations & Availability. Ra-dars are listed in Annex J1 (for naval vessels). Theyhave a detection range that depends on the contactssize and the radars function. The function describesthe kind of contacts a radar can see. Surface searchradars are designed to detect surface contacts,although very low ying aircraft can also be seen.Air search radars look principally for aircraft. Height-nding radars are used to nd the altitude of an airtarget; extremely important for ghter interception.


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5.2.2 Detection by Radar. Early radars werenot easy to use, primarily because of their display.First generation, or Gen 1, radars used A-scopes,an oscilloscope which only displayed range informa-tion in the direction the antenna was pointing. Theseradars have a 60% chance of detecting targets withinrange. Second generation, or Gen 2, radars usedthe more familiar Planned Position Indicator or PPIdisplay. These radars have a 70% chance of detect-ing targets within range. The die roll for each radar to detect a contactis made during the Detection Phase. If the roll isunsuccessful, players can try detecting the same uniton following turns, as long as it is within the radarsrange. Once detected, the contact will not be lostunless the radar is put out of action, turned off, thecontact moves out of detection range, moves belowbeyond the radar horizon, or is masked behind ter-rain. Radar gun re directors could also be used assearch radars, but they were not designed for thispurpose. The controlling player must pick a sector90 wide for the radar director to search. The sectorcan be changed each Tacti-cal Turn. Because theseradars use A-scopes, the probability of detection is60% regardless of generation. Gun re control radarswere not designed to be operated for very longperiods of time in a search mode. When a re controlradar is used for search, there is a 10% cumulativechance each Intermediate Turn that the radar breaksdown. See equipment serviceability in section 8.4 forrepair rules. Gun re radars do not have to make adie roll to detect a target if they are cued and placed

on the target by another sensor (another radar or anoptical director). The range of a radar depends as much on thesize of a contact as it does on the size of the antennaor transmitting power. The larger the contact, the far-ther away a radar can detect it. The detection ranges(in nm) are given in Annex J for Large, Medium,Small, Very Small, or Stealthy contacts. These sizesare described in section 2.4 and will be listed in An-nex A or B for each unit. 5.2.3 Shipboard Radars. The characteristicsof shipboard radars are listed in Annex J1. Surfacesearch (SS) radars are medium-range sets that can

pick up ships, land and air contacts at Very Low alti-tude. 5.2.6.1 Sea State Effects. The detection rangeof a radar searching for contacts on the sea surfaceand at Very Low altitude is reduced by sea clutter.This effect is caused by the radar beams striking thewave tops and being re ected back. The bigger thewaves, the more clutter that appears on the scope.Larger waves also cause a ship to pitch and roll,causing the antenna to point in the wrong direction.

Sea clutter is all around the ship and will affect aradars performance regardless of the contacts bear-ing. 5.2.6.3 Land Mass Effects. Nearby land is amuch better radar re ector than waves. Groundclutter can cause a signi cant reduction in a searchradars range. Air search radar beams are angled up,so they are only affected by land clutter if they areattempting to detect contacts at Low altitude. The magnitude of the ground clutter depends onthe type of terrain that the radar beam sees. Groundclutter is directionally dependent and is only effectiveif it is present within the radars maximum range andwithin 5 of the targets bearing. 5.2.6.4 Clutter Effects. In CaS , only the larg-est clutter value is used to nd out the reduction toa radars range. The other sources are low enoughthat they can be ignored without signi cantly affectingaccuracy. At the beginning of a scenario, note if there isany land or rain present in the setup and environ-ment sections. If so, record the type of terrain and/orthe type of rain. Also note the sea state. Consult theRadar Clutter Value Table on page 5-4 and nd theclutter values for each source. During the DetectionPhase of each turn, note which clutter sources areapplicable to the particular situation and use only thelargest value to reduce the radars performance. Although limited, early radars could reject orreduce the effects of clutter. This clutter rejectionwas mainly done though gain control (reducing thepower in the radar signal) and, in later radars, betterdisplays. First generation radars have a clutter rejec-

tion value of 2, while second generation radars havea clutter rejection value of 5. Subtract the radars clutter rejection value fromthe largest clutter source to nd the net clutter valuefor the radar. Take this value to the Clutter EffectsTable and cross-index to nd the radar range modi-er. Example: A US destroyer with an SC radar at-tempts to detect a Japanese DD at night as it speedsalong the coastline of Guadalcanal (terrain type isat land with light woods). The seas are a little roughat sea state 4, and there are moderate rain squallsin the area. During the Detection Phase, the US

destroyer is 11 nm away from the coastline with theJapanese destroyer at a range of 3.5 nm. Presently,there is moderate rain between the two ships. First, the maximum SS range of an SC radaris 10 nm. With the coastline farther away than 10nm, ground clutter is not a factor. The clutter valuesfrom sea state and rain are 3 and 5 respectively.Since the rain effect is the largest, the clutter valueused is 5. Note: if the US was one mile closer toGuadalcanal, then the ground clutter would havetaken over with a value of 6.


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Command at Sea 8

Next apply the clutter rejection value of the radar.Since the SC is a Gen 1 system, it has a clutterrejection value of 2. Subtract this from the rain clutterto nd the net clutter value, which in this case is 3. Referring to the Clutter Effects Table, the radarsrange is reduced to 60% of its listed value. The SCsrange for a small target is 4 nm. The modi ed rangeis thus 2.4 nm, and the Japanese destroyer slips byout of range. If the US ship had been equipped with an SGb(Gen 2) SS radar, then the results would have been: Max Range of SGb = 22 nm, ground clutter is within range Clutter Value = 6 (dominated by ground clutter)

Gen 2 Clutter Rejection = 5 Net clutter = 1 and results in a radar modi er of0.85. SG range to a small target = 15 nm Modi ed radar range = 12.8 nm The Japanese DD easily within range

5.4.1 Making Visual Detections. First, refer tothe Surface-to-Surface Visibility Tables on page 5-11and nd the table for the scenarios sighting condi-tions (e.g., 50%). Then, apply any sighting conditionsmodi ers listed on page 5-12. These cover situationsthat actually improve or degrade the visibility condi-tions, and may increase or decrease the effectivevisibility, and the table that is actually used. Example: At night with a half moon, visibility isnormally 30%. A small craft (size class E - G) at 5knots or less lowers the effective visibility by onetable, making the effective visibility 20%.

Second, on the appropriate Visibility Table,cross-index the size class of the two vessels involvedto nd the base sighting range. Third, nd any applicable modi ers to the de-tection chance on page 5-12. Roll D10, adding orsubtracting any modi ers, and refer to the VisibilityVariation Table at the bottom of this page. Multiplythe base sighting range by the value from the Varia-tion Table. This is the modi ed sighting range for thatTactical Turn. Any unit within the modi ed sighting range isdetected. Submarine periscope feathers, or wakes,(speed 5 knots or more) are treated as size class G

targets. See 5.4.2 for detection chance. 5.4.1.1 Sighting from Ships. The farthest sight-ing range for a ship is affected by its height of eye,the distance of the observer above the water. Thehigher the observer, the greater the visual horizon. This horizon is reduced by the sighting conditionsto give the effective range in the existing sightingconditions. The Surface-to-Surface Sighting Tableincludes the modi ed horizon distances. 5.4.1.4 Sighting Torpedo Launches. Play-ers have a chance to see an enemy ship launching

torpedoes. Even though torpedoes were launched byvarious means, all had some telltale signature. Thismight be the ash of a pyrotechnic charge or a cloudof vapor from condensed air. Torpedo launches are detectable at twice thedistance of a periscope. Roll Visibility Variation nor-mally. If the ship is also ring its main or secondarybatteries, reduce the detection chance by 20%. Example: On a clear day, a Japanese DD resa torpedo from 10 kyds against a cruiser. For 100%visibility, the torpedo ring could be seen at 8 kyds(twice 4 kyds), modi ed by the visibility variation roll. 5.4.1.5 Sighting Torpedo Wakes. Torpedowakes could be detected by alert lookouts, some-times in time for the ship to maneuver and comb thewake of the incoming weapons. Torpedo wakes aredetectable at the same distance as a periscope, butwith no visibility variation. If the torpedo is within sighting range, then rollD100 to see if the wakes are spotted: If the attacking torpedo uses steam propulsion,the chance of seeing it is: In daylight: 20% In morning or twilight: 15% At night: 25% Launch sighted +50% Flaming Datum +35% Electric torpedoes are wakeless, and cannot bevisually detected. Torpedo wakes cannot be visually detected insea states greater than four. If an attacking torpedo is detected, the threat-ened ship is allowed to disregard its plotted move-

ment and maneuver freely in the following MovementPhase. Aircraft torpedoes are considered to be automat-ically sighted, and this is built into their attack table. 5.4.5 Nighttime Illumination. A unit can bedetected visually at night, but it is still a poor gunnerytarget. Without a light source of some kind, a ship isonly a shadow, with its shape, course, and even itsdirection uncertain. A target must be illuminated forvisually-controlled gun re to be fully effective. Thereare many ways of doing this. Searchlights can be manually or radar-controlled.Radar-controlled searchlights are land-based. Flares

include aircraft-dropped ares and starshells red byguns. Searchlights, ares, and starshells are limitedby weather. If the weather conditions include precipi-tation, then halve the illumination radius. Ships or land bases may also use their ownlights. Normal running lights and other nighttimeillumination were usually kept off, blacked out, ifthere was a chance of attack. Use of lights will allowoperations at night or poor weather, but the units us-ing them are illuminated.


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Command at Sea 9

Any ship which is illuminated by any means istreated as a normal daylight gunnery target, ignor-ing the visibility modi ers (less than 20% and lessthan 40% visibility, see Gun re Hit Chance Modi ersTable, page 6-2 and 6-3). 5.4.5.1 Ship-Based Searchlights. Ships wereequipped with searchlights to illuminate targets innight surface actions. Searchlights have a range of8 kyds (4 nm). Any ship in the beam of a searchlightis illuminated. Any ship using searchlights is also il-luminated itself. Small Craft were normally tted with a small,low-power searchlight. These can be used like othership-mounted searchlights, but have a range of only2,000 yards (1 nm). Searchlight illumination is ordered during thePlotting Phase, and is available for targeting in thePlanned Fire Phase of that turn. A searchlight canonly illuminate a target once it has been detected,either by radar or visually. New targets found in theDetection Phase cannot be illuminated until the fol-lowing Planned Fire Phase. It takes a little time tocoach the searchlight operator onto the target. 5.4.5.5. Firing Starshells. Starshells can beused to illuminate a surface target. They may bered by a minor combatants primary battery, a majorcombatants secondary battery, or sometimes by aspecial gun. In the Plotting Phase or Reaction FirePhase, choose one mount (it must be able to rein the desired direction) to re illumination rounds(starshell). That mount may do nothing else while thetarget is being illuminated. Resolve the starshell gun for hits or misses and

the location of the illumination. In the next re phase,either the Reaction Fire Phase or the Planned FirePhase of the next Tactical Turn, the rest of the shipsguns can re and bene t from any illumination thestarshells provide. Other ships can also re at theilluminated target. Starshell illumination actually requires a seriesof shells, red over the entire three-minute Tacti-cal Turn. Individual starshells burn out quickly and ifthe mount ceases re, the light quickly fades. If themount stops at the end of a turn or shifts to anothertarget, the target ceases being illuminated in thefollowing re phase. Starshell must be renewed for

each Tactical Turn. Starshells have a minimum range of 4,000 yards(2 nm). Inside that range, the shell is moving too fastfor the chute to deploy without shredding. Starshellscannot be red into the Extreme range band. In ad-dition to accuracy problems at Extreme range, at thisdistance the altitude of the shell is so low when it ig-nites that there is no useful illumination. If a starshellmisses a target and goes into the Extreme rangeband, it automatically fails.

The player rolls the chance to hit for the gunnormally, except that he should ignore the targetsaspect. If it is a hit, the starshells land at the desiredlocation, either a plotted point on land or a designat-ed ship. If they miss, roll D10 again. On a 1-5, the relands 1,000 to 3,000 yards short. On a 6-10, it lands1,000 - 3,000 yards long.

Starshell Miss Table D10 roll Miss distance 1 3000 short 2 2500 short 3 2000 short 4 1500 short 5 1000 short 6 1000 long 7 1500 long 8 2000 long 9 2500 long 10 3000 long

If the modi ed range is inside the starshells mini-mum range of 4,000 yards (2 nm), the chute shredsand it fails to function. Any unit within 1,000 yards (one-half nm) ofthe point is immediately illuminated for the next rephase. Units between the starshells and another unitare silhouetted to a range of 6 kyds from the point ofimpact. 5.4.6. Smoke Effects. Smoke was used in WW IIto obscure a target and reduce its chance of being hitduring an attack. It could also reveal a targets loca-tion.

Smoke generators could be land-based, po-sitioned around some valuable installation. Theywere also carried by destroyers, and used to screenother ships from gun re attack or accurate torpedore. Visibility in or through a dense smoke screen isreduced to 1,000 yards (.5 nm) in the daytime and500 yards (.25 nm) at night. That is, to see a ship ina smokescreen the observer must be within 1,000yards in the daytime and 500 yards at night. On thelast turn that the smoke exists, it is dissipating andthe surface visibility is reduced to 1/4 of the unob-structed visibility. Smoke does not block radar detection, so

radar-controlled gun re or bombing is not affectedby smoke. Gun re spotting aircraft are not affectedunless the target is actually in the smoke screen. If a ship moves into smoke during the MovementPhase, and ends the phase within the smoke, it maystill be red on if it spent at least half of its movementoutside the smoke. If the ship is obscured for morethan half but not all of the turn, all gun re suffers a-4 dead reckoning penalty for that turn only. This isless than the normal blind re modi er (-6), since theships location was known before it became ob-


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Command at Sea 10

scured. If the ship remains hidden on following turns,it cant be red on at all. 5.4.6.1. Shipboard Smoke Screens can be cre-ated in any Plotting Phase. In the Movement Phaseof that turn, a ship will leave a smoke screen in itswake. The smoke screen can be turned on or offeach turn as the player desires. The screen extendsonly a few hundred feet into the air. It does not blockline of sight from aircraft at Low altitude, but willblock planes ying at VLow. The smoke screen willremain for four Tactical Turns (in calm weather), thendisperse. Reduce this time by one turn for every 10 knotsof wind. (e.g., If it is from 1 - 10 knots, it will last threeturns. If the wind is 11 - 20 knots, the smoke screenwill only last two turns.) Smoke is removed at the endof the Plotting Phase of the turn in which it disap-pears.

Chapter Six - Surface Combat 6.1.1 Directors. Main batteries on all combatantsand secondary batteries on major combatants are t-ted with optical directors. If a gun battery is tted withre control radar, it will be listed on the weapons linein Annex A. If a ship is tted with more than one GFCradar for a battery, it will be listed as such. GFC radaris also lost when the re control is knocked out. Major combatants are tted with more than onedirector for their gun batteries. This was necessarybecause one director could not provide complete360 coverage, and it also allowed the ship to en-gage more than one target with a battery. Major combatants will always have two direc-

tors for their main battery, arranged with F/A arcs.The forward director is the primary one, and the afterdirector was usually lower, so that when it is used theship should be treated as one size class smaller fordetecting targets for that director to engage. Major combatants will also have two secondarybattery directors, usually arranged P/S. If the second-ary battery is arranged so that it includes the forwardand after arcs only, then the directors will also haveF/A arcs. If the secondary battery includes both theforward, aft, port, and starboard arcs, then there willbe four secondary battery directors, with F/P/S/Acoverage.

Minor combatants will have one director with aforward arc for the main battery. This means that ifthe player wishes to have an aft mount engage atarget to the rear, it must do so in local control. 6.1.2 Gun re in Local Control. Guns can bered without their director, in Local Control. Anygun mount can be put in local control by ordering itin the Plotting Phase. In local control, the crew of thegun mount aim and re the gun themselves. This isthe normal procedure when the director has beenknocked out.

Depending on the gunnery standard, a negativemodi er is applied when ring in local control. The gun director is located at one of the highestpoints on the ship, while the gun mounts and theirsights are mounted much lower, usually on the maindeck itself. This meant that if the gun crew dependedon the mounts sights, the visual horizon and spottingrange was reduced. In local control, reduce the shipssize one class. 6.1.3 Gunnery Procedure. Gun ranges aredivided into four range bands: Short, Medium, Long,and Extreme. In Gunnery Standard 4 (GS4), a gun ring atShort range has a base 60% chance to hit. A Me-dium-range shot has a 40% chance, a Long-rangeshot has a 15% chance, and an Extreme-range shotis only 5%. These chances can be changed up ordown by various modi ers. The chance to hit cannotbe raised over 90%, even with modi ers. While the base hit chances are the same, thesize of the range bands vary for each gun. A US16/50 has a short range of 8,500 yards, over fournautical miles, while a Japanese 10th Year Type4.7"/45 has a short range of 5,300 yards. Procedure: Measure the range from the ringship to the target and note the targets aspect (broad,narrow, or quarter). Choose the proper range band(short, medium, long, or extreme) by comparing themeasured range with the numbers for that gun inAnnex C. Count the number of barrels ring. Be sureto check arcs of re (section 2.2.2) and that the gunscan actually re on the target. Adjust the chance to hit up or down by using the

Gun re Hit Chance Modi ers Table (page 6-2). To dothis, total up the modi ers that apply to the shot, andmultiply it by 4% at short or medium range, and 2%at long or extreme range, and then add or subtract itfrom the base chance to hit. If a target is at long or extreme range, and themodi ed hit chance is zero, a ship can re a rangingshot. This counts toward the consecutive turn gun-re modi ers, but it has no chance of hitting. If themodi ed hit chance is less than zero, there is no recontrol solution, so there would be no bene t from aranging shot. Roll D100. If the roll is less than or equal to the

modi ed chance to hit, the target has been hit. Note the number of damage points in icted bythe gun in that range band (found in Annex C). Lookon the Gun Damage Multiplier Table (page 6-5) andcross-index the number of barrels ring and therange band. This gives a multiplier for the damagein icted in Annex C. Multiply the two numbers to getthe number of damage points suffered by the target.Guns that re only in the Reaction Fire Phase (inresponse to a newly-detected target) have their dam-age halved.


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Command at Sea 11

Players do not have to keep track of gun am-munition, unless required by a scenario. It is veryrare for a naval gun mount to run out of ammunitionduring an engagement. 6.1.4 Overconcentration. Optical directors andeven radar could only get the shells close to theenemy ship. Adjusting the re required being ableto see the shell splashes and correct the next salvobased on whether they were long or short of the tar-get. These corrections were added manually, by thedirector operator. If a second ship res at the same target, thedirector operator will have a hard time telling whichshell splashes belong to him and which belong tothe other ship. A third ship makes the problem evenworse, and so on. Overconcentration will occur if the shell splashesare roughly the same size. No battleship would beconfused by the splashes of a destroyer ring at thesame target, but a battleship with 16-inch guns wouldnot be able to tell its splashes from those of 15-inch guns also ring at the same target. For guringoverconcentration, large shells are 11 to 18 inches,medium shells are 5.9 to 10.9 inches, and smallshells are less than 5.9 inch diameter. If more than one ship res at the same target,all the ships ring the same size guns at that targetat Long and Extreme range are subject to a gun hitchance modi er equal to the number of ships ring atthat target minus one. Example: A heavy cruiser is red on by a battle-ships main (15 inch) and secondary (5 inch) batter-ies, two heavy cruisers main (8 inch) and secondary

(4.5 in) batteries, and one destroyer (4 inch). All gunsare ring at Long or Extreme Range. The overcon-centration penalties are: BB main battery: no overconcentration, onlyone ship ring shells of that size. CA main battery: Two ships ring medium-sizedshells, penalty of -1. DD & BB & CA secondaries: 1 DD + 2 CA +1BB, four ships total, penalty of -3. 6.1.6 Line of Fire Restrictions. A ships line ofre to a target may be blocked. This will happen ifanother ship is in the guns Short or Medium rangeband and is within 10 of the line of re (20 total

arc). Land of 100 m elevation or more will block aships line of sight, although a plane may provideover-the-horizon spotting to replace it. Land of lessthan 100 meters elevation may still block line of sight.This will be speci ed in the scenario description. Ships carrying oatplanes on after catapults havetheir line of re blocked 30 of centerline aft formain and secondary batteries. The muzzle blast fromeven a medium-caliber gun was enough to damagea plane or even start a re. If a ships main or sec-

ondary battery res within 30 of the aft centerlinewhen there are oatplanes on aft catapults, there is a50% chance they will be damaged (roll each TacticalTurn). Treat it as an aircraft critical hit.

6.3 Surface-Launched Torpedoes. Torpe-does must be red against a detected target, or are control solution against a blind target must beachieved. They cannot hit small craft, such as PTboats or barges (size classes E-G). Range for torpedoes is measured from the geo-graphic point of ring to the torpedos current posi-tion. If the distance traveled by the torpedo since itslaunch is greater than the listed range, the torpedoruns out of fuel and automatically misses. A ship mayreveal its bearing when it res a torpedo against anyship with effective sonar. The following rules apply to torpedo attacks fromsurface ships and submarines. 6.3.1 Straight-Running Torpedoes. Most tor-pedoes used in WW II can have their gyro set to runon a particular course, which need not be the samedirection as the launching tube is facing. They can beset to a course anywhere within the tubes ring arc. The Soviets were still using an earlier form ofstraight-running torpedo, which required that thelaunching tube (and the submarine) be pointeddirectly along the intended course. These torpedoesare noted in Annex F as being non-gyro straightrunners. In most cases, the speed of a torpedo is not thatmuch greater than that of its target. This means theDe ection Angle, the amount of lead, must be very

large. CaS players can use the Torpedo De ectionAngle Table to compute their own lead angle andre their spreads. On the turn of launch, a ship is allowed to makeone turn (within normal maneuvering limits) at thebeginning of the three-minute Tactical Turn, butafterwards must steer in a straight line. Surface shipscannot use evasive steering, and submarines cannotevade depth charges. Torpedoes must be set at the time of launch torun shallow or deep. Shallow weapons will hit anysize class D or larger ship, but will strike the beltarmor of size class A or B ships, which reduces their

effectiveness. Deep torpedoes will run under sizeclasses C and D, but will hit an A or B ship on theunderwater hull, instead of the armor. On the turn of launch, unless hidden movementis being used, place a torpedo counter next to thering ship, along with a Datum marker that will let theplayer measure the length of the torpedos run. Movethe torpedo marker in the Movement Phase of follow-ing turns. There is a chance that the torpedo launch can beseen (see section 5.4.1.4).


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After a torpedo is launched, its course cannot bechanged. Torpedo Movement to Target. In every Move-ment Phase of the turn after they were red, torpe-does move at their rated speed in a straight line onthe course ordered by the player (within the tubesring arc). Depending on the targets maneuvers afterlaunch, it may or may not be at the expected point ofintercept. In addition, another ship (friendly as well asenemy) may be struck by the torpedoes if it gets inthe way. If a torpedo spread comes within 500 yards(1,000 yards total width) of any eligible torpedotarget, that unit is attacked by the spread, and thetorpedo attack should be resolved against it. Torpedoes move like any other surface ship orsub. If there appears to be a chance of a torpedospread and a ships path intersecting, use propor-tional movement to see if the torpedoes pass closeenough to resolve an attack. If the players are notusing a referee, they will have to plot movement oneturn ahead. See section 2.6. 6.3.2 Resolving Torpedo Attacks. When atorpedo reaches a ship (its intended target or anotherthat gets in the way) the attacking player must roll tosee how many torpedoes actually hit. This is basedon the targets size (battleship, cruiser, destroyer,etc.) and the angle from which the torpedoes attack.A side shot on a destroyer stands a better chance ofhitting than a bow-on attack on a battleship. Find the targets effective length by using theAspect Table on page 6-15. First look at the diagram to see from what angle

the torpedoes are attacking the ship. The degreenumbers around the edges of the box refer to relativebearing, in other words, the bearing of the torpedorelative to the ships bow. Most shots will be on oneof the quarters. Broad is the best, narrow is theworst. Cross-indexing the ships real size with its angle,the resulting Roman numeral is the table to use toresolve the attack. Attack Table I is the best, AttackTable VI is the worst. Once on the correct Torpedo Attack Table (pag-es 6-13 through 20), choose the appropriate chart forthe number of torpedoes in the spread. There are six

charts, the maximum spread being six weapons. Now measure the range from the impact pointback to the ring point. Note: torpedo run at impactis not necessarily the same as target range at time ofre. The range that matters is not the range at ring,but at impact. This is how far the torpedo has actuallytraveled, and this is what affects its chance to hit. Look down the range column for the range clos-est to the torpedos run. Round even splits up, i.e.,8,500 yards becomes 9,000 yards.

Roll D100, and starting at the right, compare theresult to the hit chances in the corresponding row.If the die roll is less than or equal to that value, thenumber at the top of the column is the number oftorpedoes that have hit the target. If the die roll isgreater than that number, look at the next number tothe left in that row and compare the die roll with it. As the number rolled gets bigger, the number oftorpedoes hitting gets smaller. If the die roll is biggerthan the number in the column with 1 at the top, allthe torpedoes in the spread missed. Any torpedoes in the spread that miss the in-tended target have the opportunity to hit other nearbytargets, if they exist. However, only the rst target isattacked by the full spread. All remaining torpedoesare treated as individual weapons i.e. spread size =1.The only exception to this rule is if the salvo missesthe rst target completely, then the second targetin the torpedoes path would be attacked by the fullsalvo. If the target ship is stationary (speed zero, deadin the water), move two lines up on the torpedo table.

6.7 Combat Considerations. Combat is restrict-ed by the following considerations. 6.7.1 Weapons Danger Space. Surface shipsmay not re their guns at other surface targets iffriendly ships are in the line of re. The danger areabetween the rer and the target is within 10 of eitherside of the line of re in the guns Short and Mediumrange band. By the time a shell has passed into theLong range band it is high enough so that it will passover any friendly ships.

For a friendly ship to be included in the weaponsdanger space surrounding an enemy ship, it must beinside the space for at least half of the enemy shipsMovement Phase. There is a second danger space directly aroundthe target. It lies within 5 of the line of re and tenpercent of the range between the rer and the target. If a friendly or enemy ship passes through eitherdanger space, it is also subject to an attack at halfthe modi ed chance to hit and if hit, half the damagefor that range band. This danger space represents the occasionalshell that does not follow a predicted ballistic path,

an unexpected roll that a stabilization system cannotaccount for, or aiming errors by the director. Sucherrors would usually just include a single shell or asingle salvo, but the damage values in Annex C actu-ally represent only a few shells out of the many redactually striking an intended target. 6.7.2 Rates of Fire. If a weapon does not havea rate of re listed in the remarks section of Annex Afor that ship, it may re once per rail or tube per turn.Guns may be ring many rounds, depending on theirbore, and multiple-barreled weapons, like the Mouse-


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Command at Sea 13

trap series, will re all their tubes in one salvo orpattern.

Chapter Eight - Damage 8.1. Applying Damage. Whenever a Size ClassA - D ship is hit by a weapon, subtract the damagepoints in icted by the weapon from the ships dam-age point total. When the ships total reaches zerothe ship sinks. When a weapon in icts damage on a target, theweapon must penetrate any armor in the location ofthe hit before it can do internal damage. Non-pen-etrating hits will cause less damage (see 8.1.6). The effects of damage, including critical hits, areapplied simultaneously to both sides at the end of thephase. Damage from re or ooding critical hits is ap-plied in the Resolution Phase of the third turn afterthe critical hit is in icted, with two exceptions: Flood-ing from torpedo hits is applied immediately, in theMovement Phase the torpedo hits. Flooding and Firecriticals are in icted on Small Craft (Size class E - G)immediately. Secondary effects from criticals, like explosions,are applied immediately, in the phase in which thedamage is resolved. Movement Phase . Resolve torpedo and mineattacks. Planned Fire Phase . Gun re, ASW ahead-thrown weapons, and depth charge attacks made inthis phase are resolved in this phase, including dam-age effects. Detection Phase . No combat resolution occurs.

Reaction Fire Phase . Resolve gun re anddepth charge attacks made in this phase. Resolution Phase . Fire and ooding criticalsare resolved. 8.1.1 Speed Reduction. As a ship or subs dam-age point total is reduced, its speed goes down aswell. Loss of structural strength may force a ship toslow down. Drag on the hull will slow it as its smoothlines are broken by holes and other damage, andgeneral damage to the propulsion plant will affect itsef ciency. A ships speed is reduced by one quarter eachtime it takes one quarter of its original damage point

level, and is reduced to zero at the 90% damagelevel. The break points for damage are 0%, 25%, 50%,75%, 90%, and 100%. The speed percentages are100%, 75%, 50%, 25%, 0%, and sunk. Each ship class has a different table which isincluded with its other characteristics in Annex A. Thetop line represents the damage point levels wherethe speed is reduced, while the bottom line showsthe new maximum speed at that level of damage.

Example: The Japanese heavy cruiser Myoko takes 346 points of damage. Its damage and speedbreakdown table is shown below:

Damage and Speed Breakdown:Dam Pts: 0 87 173 260 311 346Surf Speed: 33 25 16 8 0 Sinks

With no damage (0), Myokos max speed is 33knots. With 86 points of accumulated damage, shecan still do 33 knots, assuming no propulsion criti-cals or other restrictions. At 87 points, though, hermaximum speed is reduced to 25 knots. From 87-172points of damage, she can make 25 knots. The 173rdpoint reduces her speed to 16 knots, and so on. Acceleration/Deceleration rules (section 3.1.1)apply here, so the ship slows, coasting to a slowerspeed at half the deceleration rate, so its speed nextturn would be 33 - (12/2) = 27 knots. The followingturn it would slow to its new maximum speed, 25knots. If a ship has taken propulsion criticals or otherdamage that also reduces its speed, these are ap-plied to the ships current maximum speed. 8.1.2 Ship & Sub Critical Hits. A ship can bedestroyed by sinking it, but it can also be rendereduseless by destroying the equipment that makes i t awarship. This is called a mission kill. Damage to a vital component of the ship is calleda critical hit. These include not only weapons andsensors, but engineering (propulsion), the rudder,and ight decks. In each phase that a ship takes damage, divide

the damage points taken by the points the ship hasremaining after that phases damage points are ap-plied. This is the damage ratio used to gure out howmany critical hits a ship may have suffered. Example: A Fletcher class destroyer has 84damage points. If it takes 22 points of damage fromgun re in the Planned Fire Phase, the damage ratiois 22/(84-22) or 22/62 = .35. Since the damage ratiois always rounded down, this will be rolled on the .30line. Minimum Damage: Ships must suffer somemeasurable damage before they must roll for criticalhits. If the critical hit ratio is less than 1% of the ships

original damage points, then no criticals are in icted.This prevents destroyers from being sunk by a sub-machine gun. Roll D6 and cross-index the result with the dam-age ratio on the Damage Ratio Table (page 8-2).The result is the number of critical hits in icted on theship.


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Example: After suffering damage, a Fletcher class destroyer has a damage ratio of .35. The at-tacking player rolls D6, using the .30 line (alwaysround down). The result is a 4, and the Fletcher suf-fers two critical hits. Once the players know how many critical hitshave been in icted, nd the nature of each on theCritical Hit Table (page 8-2). Each type of ship has itsown column. Roll D20 for each critical hit on that col-umn to see what its effect on the ship is. The criticalhit types with asterisks (*) are protected by the shipsarmor, if it has any. If the armor was not penetratedthat turn, the critical is ignored. Some weapons will automatically in ict sometypes of critical hits, in addition to any generated bydamage points: Each contact-fused torpedo that hits a ship willautomatically in ict a ooding critical, in addition toany other critical hits. A ships torpedo protection sys-tem (see section 8.1.7.2) must be penetrated beforethe automatic ooding critical hit occurs. Any ship that takes 75% or more damage froma single bomb, torpedo or mine hit must roll D10. Fortorpedoes or mines, on a 1 - 8, and for bombs on a1 - 4, the keel has been broken and the ship will sinkper section 8.1.8. 8.1.6 Effects of Armor. In World War II, shipslarger than a destroyer carried armor covering themagazines and engineering spaces (belt), majorweapons (turret top and faces), and the deck. Othercritical items, such as the conning station, couldalso be armored. The armor belt provided protectionagainst close-range shell re and shallow torpedoes.

The deck provided protection from bombs andplunging re at long ranges. Each weapon has a penetration rating as partof its statistics. These values are precalculated foreach gun at each range bracket, and are listed inAnnex C. To nd a guns penetration, measure therange and nd the appropriate range band in theannex for that gun and shell type. The most commonshell types are Armor-Piercing (AP), High Explosive(HE), Semi-Armor Piercing (SAP), Common (COM),and Special Common (SpCOM). Short and Medium-range gun re has a relativelyat trajectory, and will strike the side of a ship on

its armor belt. Long and Extreme-range re mustarc much higher and is called plunging re. At Longrange, there is a 40%/60% chance the shell re willstrike the belt or deck armor, and the ring playermust roll to see which armor value must be penetrat-ed. Extreme-range shell re has a 30%/70% chanceof striking the belt or deck armor. Deck and belt armor ratings are provided foreach ship. For example, Baltimore class heavycruisers have a rating of 13/6, meaning a belt thick-ness equivalent to 13 centimeters, and a deck armor

equivalent to 6cm. The deck is much thinner thanthe belt, but shells at Long range do not penetrate asmuch armor and the chance of getting a hit is muchless as well. Compare the penetration ability of the weaponwith the armor rating where it struck (deck or belt). Ifthe weapons penetration is greater than the armorrating, it in icts full damage. If it does not penetrate,halve the number of damage points in icted. If the weapon does not penetrate, certain criticalhits cannot happen. These are marked with an aster-isk (*) on the critical hit table. 8.1.7 Armor and Torpedoes. Torpedoes canbe set to run shallow or deep. Torpedoes must runshallow to hit size C-class (destroyer) and smallerships. A shallow torpedo will strike a larger ships beltarmor, however. Deep torpedoes will run under smallships and will strike larger ships below the belt armor,on their torpedo bulges if they have any. While somelarge ships carried torpedo protection systems manydid not. Whatever their depth, torpedoes that strike a shipfrom the narrow aspect (see the diagrams on 2-6 or6-15) strike outside the armor belt or the torpedo pro-tection system. Divide the torpedos damage by two.An extreme bow or stern hit wasted a lot of its energymoving water and not damaging the ship. If the narrow aspect hit is in the stern, the rsttwo critical hits (beside the automatic ooding, whichdoesnt count against the critical hit number) areautomatically engineering and rudder hits. Roll theremaining critical hits as per sections 8.1.2. 8.1.7.1 Shallow-Running Torpedoes. If a shal-

low-running torpedo strikes the armor belt, its dam-age is reduced according to the following table.

Targets Damage Point Belt Armor Reduction 0-5 None 5-10 10% 11-20 25% 21-30 40% 31-40 50%

8.1.8 Sinking. A ship or surfaced sub that hasreceived damage suf cient to sink it rolls D10*10 for

the number of minutes it will take to sink; the nal dis-appearance occurring during the Movement Phase.Submerged submarines and ships that have maga-zine explosions sink immediately. 8.1.10 Massive Damage. Even though some ofa ships weapons may still be intact, there is a timewhere overall damage to a ship will prevent theiroperation. When a ship has only 25% of its original damagepoints left, all main, secondary, and tertiary (if tted)battery weapons are out of action. Subs must sur-


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Command at Sea 15

face. Aircraft carriers cannot launch or land aircrafton the ight deck. When a ship has only 10% of its original damagepoints left, all of its weapons, including light AA andcatapults, are out of action.

8.2 Fire & Flooding Critical Hits. Either a rehas started, or the ships watertight integrity has beenviolated (that sounds better than, theres a hole inthe hull). For each ooding or re critical, roll to see howsevere the casualty is:

Ships in Fire & Flooding service date Severity 1907 and earlier 2D6+2 1908 - 1924 D6+2 1925 and on D6

Modi ers: 1) Halve the result if the hit is non-penetrating. 2) Halve the result if it is caused by guns of76mm or less

The result is a percentage of the ships original(undamaged) DP. These damage points are in ictedon the third Tactical Turn after the critical hit and oneach Intermediate Turn after that, until the criticalis removed ( exception: ooding critical hit damagecaused by mines or torpedoes is applied immedi-ately). Example: On turn 1506 of a gun battle, the heavycruiser Prinz Eugen succeeds in hitting the battlec-

ruiser Hood (commissioned in 1920). The Britishplayer rolls for the type of critical hits, and one ofthem is a re. Using the second line of the table, theBritish player rolls a 5, meaning the re in icts 7% ofHoods undamaged rating each Intermediate Turn.However, because the hit didnt penetrate Hoods armor, the damage is reduced to 3% (3.5% roundeddown). Hoods undamaged DP rating is 753, so shesuffers 22 damage points in the Plotting Phase ofturn 1515. Hood will have to roll in the ResolutionPhase of 1515 to see if the re damage causes anynew criticals. Record the time the critical was in icted and its

severity as a percentage. When guring out what line of the table to use,look at the ships in service date in Annex A. Alsocheck the remarks to see if the ships has been re-constructed. For instance, the Japanese battlecruiserKongo entered service in 1913, but was rebuilt in1937, improving her resistance to re and ooding.She should use the third line, covering 1925 and on.

Fire & Flooding Severity Levels. Total up thepercentage of the re and ooding critical hits from

either existing or newly in icted hits. For example,a ship with two res at 4% and 9% and a 3% ood-ing critical has a total percentage of 16%. This is theseverity level. It affects how well the damage controlteams will be able to ght the casualties, and if itsbad enough, will affect the ships ability to move andght. The ships damage control ability is affected byits size:

Severity Level Size Over-Class Minor Major Severe whelmedA - B 1 - 10% 11 - 15% 16 - 17% 18%+C - D 1 - 8% 9 - 12% 13 - 14% 15%+E - G 1 - 6% 7 - 10% 11 - 12% 13%+

These levels are modi ed by the age of the ship.Over time, designers have made ships more resistantto damage.

Ship In %Service Date Reduction1907 -2%1908 - 1924 -1%1925 - 1941 0%1942 - 1959 +1%1960+ +2%

Example: HMS Hood was built in 1920, so herseverity levels would be 9%/14%/16%/17%

If the severity of the re criticals adds up to:

Major or worse: Ships must cease ight opera-tions, maneuver to put the wind 30 on either bowand slow to 15 knots or less. If they do not maneuverand reduce speed, add +2 to the die roll for reducingthe re. When applying gun re and visual detection modi-ers at night, treat the ship as illuminated. It will alsoilluminate or silhouette other ships similarly to a areor starshell. Overwhelmed: The ship is suffering a con agra-tion. There is a 25% chance, cumulative per Inter-mediate Turn, of the re reaching the ships maga-zines and causing an earth-shattering kaboom. A

ships player can prevent this by ordering the maga-zines to be ooded in the Plotting Phase. The shiploses all main battery, secondary battery, and aircraftordnance. Only Light AA ammunition is unaffected. If the severity of the ooding criticals adds upto: Major or worse: Ships must slow to 15 knots orless. Overwhelmed: The extensive ooding maycause the ship to capsize. There is a 25% chanceper Intermediate Turn of the ship capsizing. The only


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Command at Sea 17

Aircraft. An aircraft aboard the ship has beendestroyed. There is also a chance that a re hasstared. Roll D6-2% for the severity of the re. A resultof less than one means there is no re. Bridge. The main conning station has suffereda catastrophic hit. It takes D6/2 Tactical Turns tocorrect casualties and re-man the bridge. After thecasualty has been corrected, all changes to courseand speed take Two Tactical Turns to execute. Thereis a re critical hit, subtracting two from the severityroll, in the bridge/control room. Cargo. Some of the ships cargo has beendestroyed. If possible, allocate cargo to a hold/tank,then determine which hold or tank was hit. Refer tothe Cargo Damage Table (page 8-8) to see what theresults are. Communications . One of the ships communi-cations spaces has been hit. Roll D6 on the followingtable: 1 - 2: Long-range radio communications 3 - 4: Short-range radio communications 5 - 6: Aircraft radio communications Loss of long-range comms prevents the shipfrom communicating with units beyond the horizon.Losing short-range communications prevents shipsfrom using radio with other ships in the same for-mation. Aircraft radio is necessary to communicatewith any planes, whether it is a destroyer controllinginterceptors or a cruiser talking to its oatplanes or acarrier marshalling aircraft for landing. Engineering. The ships engineering plant hasbeen damaged. Reduce speed to the next lower levelon the Damage and Speed Breakdown chart. A re

critical hit, subtracting two from the severity roll, hasstarted in the engineering spaces. Light AA Battery. The ships Light AA strengthis reduced by 0.5. Main Battery. Roll D10. On a 1-2, the re con-trol for the main battery has been knocked out (armorpenetration not required). On a 3-0, one of the gunmounts/turrets in the main battery is out of action.Roll D10 again. On a roll of 10 the magazine deto-nates, destroying the ship. Ships within 500 yardsof the exploding ship suffer damage equal to thebatterys HE damage at Short range. If a main battery mount/turret is hit, roll randomly

to see which one is destroyed. All mounts/turretsare counted, even if they are already out of action. Ifthe mount has already been destroyed, there is stilla chance of the magazine detonating, but no furtherdamage is in icted. Other Weapon. One of the weapons listed forthe ship in Annex A, except main or secondary bat-tery guns, has been knocked out. Roll randomly tond out which mounts have been hit. Previously hitmounts can be hit again. If the mount has alreadybeen destroyed, there is still a chance of the maga-

zine detonating, but no further damage is in icted. Ifthere are no applicable weapons, ignore the critical. If it is a torpedo tube or an ASW weapon, refer tothat critical hit. If it is an aircraft, refer to that criticalhit. Rudder. The ships steering or control surfaceshave been damaged. Surface ships roll D6: 1 - 3: Jammed: The rudder is jammed in what-ever direction the ship is currently moving. If the shipis steering evasively or otherwise maneuvering withboth left and right rudder, roll randomly for the direc-tion of the jam: 1-2 port, 3-4 straight, 5-6 starboard. 4 - 6: Disabled: The ships steering engine hasbeen hit. Maximum speed is reduced to 1/3 of theships undamaged speed. Maximum course changesafter moving the required advance are reduced from45 to 15. Secondary Battery. Roll D10. On a 1-2, the recontrol for the secondary battery has been knockedout (armor penetration not required). On a 3-0, oneof the gun mounts/turrets in the main battery is out ofaction. Roll D10 again. On a roll of 10 the magazinedetonates, in icting four times the mounts ShortRange damage points (HE shell) on the ship. If a secondary battery mount/turret is hit, rollrandomly to see which one is destroyed. All mounts/ turrets are counted, even if they are already out ofaction. If the mount has already been destroyed,there is still a chance of the magazine detonating, butno further damage is in icted. Sensor/Communications. Roll D6: 1 - 3 Sensorcritical hit, 4 - 6: Communications critical hit. Sensor. One of the radars, sonars, ES, HF/DF,

or searchlights is destroyed. Torpedo or ASW Weapon. A torpedo mount,depth charge rail or thrower, or ahead-thrown ASWweapon has been hit. Roll D10. On a 10, the mountsammunition explodes. Multiply the damage points forone weapon times half number of weapons loaded inthe mount. If the mount has red all of its weapons,there is no danger of explosion. If a torpedo or ASW weapon does detonate, andthe mount is above the waterline, resolve critical hitsfrom the warhead damage as a bomb or gunnery at-tack. In other words, do not roll on the DC or torpedoattack table, since these columns assume under-

water impacts. Use the critical hit column that bestmatches that ships type. If a torpedo in the tube detonates, and is belowthe waterline (either on a sub or a surface ship) itin icts an automatic ooding critical, and the dam-age points should be applied as underwater damage.Battleships with submerged torpedo tubes shouldignore any torpedo protection system they are ttedwith.


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Command at Sea 18

Startup Battle

Location: Iron Bottom Sound, Solomons Islands,0000, Late 1942.

Operational Situation: American forces on Guadal-canal are struggling to defend their position aroundthe island. Japanese naval forces attempt to resupplytheir garrison during the night, while US forces do thesame in the daytime.

Tactical Situation: The Japanese BombardmentGroup is screening a run of the Tokyo Express,carrying reinforcements and supplies. The US forceis screening the Marine positions from bombardmentand also interdicting Japan-ese resupply efforts.

Environment: Night, visibility 40%, sea state 3.Dawn is 0430. There is a low overcast precluding theuse of scout planes. The islands are largely at andlightly wooded.

Japanese Forces: Bombardment Group, Aoba , Kinugasa (both Aoba class CAs) Reinforcement Group Kinryu Maru , Kinka Maru (both Kinryu Maru class transports), each carrying 4 companies of infantry and supplies. Screen Asashio , Oshio , Michishio (all Asashio class DDs)

Japanese Orders: The Bombardment Group is toshell Henderson Field. The Reinforcement Unit iscarrying troops for the offensive to retake the air eld.The reinforcements can be landed at Tassafarongaduring the bombardment.

Japanese Victory Conditions: Decisive: Both trans-ports reach Tassafaronga by 0300 hours and Hen-derson Field receives 500 points of damage. Tacti-cal: At least one transport reaches Tassafaronga by0300 hours and American damage points are doublethose sustained by the Japan-ese (counting Hender-son Field).

Allied Forces: Screening Force Portland , Indianapolis (both Portland classCA) Gridley , Craven , McCall , Maury (all Gridley class DDs)

Allied Orders: Intercept and prevent the Japanesefrom bombarding Henderson Field, and also preventenemy resupply efforts in the vicinity of TassafarongaPoint.

Allied Victory Conditions: Decisive: Allies damageboth transports over 50%, and Henderson receiveszero damage. Tactical: The Allies prevent Japanesefrom shelling Henderson eld.


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Command at Sea 19

Aoba (1940) CADisplacement: 9000 std In Class: 2Size Class: B/Medium In Service: 1940Propulsion: Steam Turbine Crew: 657 - 680Signature: Medium/Loud Armor Rtng: 6/4Weapons:2F/A(2)3 3rd Year Type No. 2 20cm/50 CP/S(1)4 10th Year Type 120mm/45 CP/S(4)2 610mm TT w/8 Type 93 torp [4 reserve torp/mount available for quick reload] F1 Midships catapult --E13A1 [Jake] BArea AA: (1)4 10th Year 4.7 in/45 (0.6)Light AA: (2)4 Type 96 25mm, (2)2 Type 93 13mm (1.2)Sensors: F/A 2 Type 94 LA re control directorsRemarks: Aoba, Kinugasa. Originally commissioned 1927; rebuilt1937 - 40. laid down before 1925, special damage modi er of-15%. Con guration listed above is after 1940 re t.Damage & Speed Breakdown:Dam Pts: 0 55 110 164 197 219Surf Speed: 33 25 16 8 0 Sinks

Asashio DDDisplacement: 1992 std In Class: 10Size Class: C/Small In Service: 1937

Propulsion: Steam Turbine Crew: 200Signature: Small/Noisy Armor Rtng: 0Weapons:F/2A(2)3 3rd Yr 5 in/50 C2 DC rail w/8 DC E(2)2 Model 94 Y-gun w/8 DC EP&S(4)2 610mm TT w/ Type 93 torp FArea AA: (2)3 3rd Yr 5 in/50 (0.7)Light AA: 4 Type 96 25mm/60 (0.5)Sensors:Type 93 (passive), Type 93 Model 1 (active) sonar KRemarks:Four Type 93 torp reloads carried for each mount. Carried specialreloading gear for TT, reload time 6 min. Total of 36 DC carried.Damage & Speed Breakdown:Dam Pts: 0 19 39 58 69 77

Surf Speed: 35 26 18 9 0 Sinks

Kinryu Maru APDisplacement: 9310 grt In Class: 2Size Class: B/Medium In Service: 1937Propulsion: Diesel Crew: 47+12Signature: Medium/Loud Armor Rtng: 0Remarks:Ex-civilian merchant ships. Merchant construction, special damagemodi er of -50%.Damage & Speed Breakdown:Dam Pts: 0 26 53 79 95 105Surf Speed: 21 16 11 5 0 Sinks

Portland CADisplacement: 9800 std In Class: 2Size Class: B/Medium In Service: 1932Propulsion: Steam Crew: 1382Signature: Medium/Noisy Armor Rtng: 7/5Weapons:2F/A(3)3 Mk14 8 in/55 CP/S(1)8 Mk23 5 in/25 C2 Midships catapult --4 SOC Seagull BArea AA: (1)8 Mk23 5 in/25 (1.7)Light AA: 8 .50 cal (0.6)Remarks:Portland, Indianapolis . Also Indianapolis class. 8 inch gunhouseslightly armored, treat as deck armor at all ranges. 1941: Portland tted with (4)1 1.1 in, Lt AA 0.9. Apr-May '42: Indianapolis re tted, .50 cal removed, (1)8 20mmand (4)4 1.1 in added, Lt AA 3.3.Damage & Speed Breakdown:Dam Pts: 0 69 138 207 248 276Surf Speed: 32 24 16 8 0 Sinks

Gridley DDDisplacement: 1590 std In Class: 4Size Class: C/Small In Service: 1937

Propulsion: Steam Crew: 158Signature: Small/Noisy Armor Rtng: 0Weapons:F/A(1)4 Mk24 5 in/38 CP/S(4)4 Mk12 533mm TT w/4 Mk15 torp F2 Mk3 DC rail w/6 Mk7 or 8 Mk6/9 DC E6 Mk6 K-guns w/6 Mk6/9 DC EArea AA: (1)4 Mk24 5 in/38 (1.1)Light AA: (1)6 20mm (1.5)Sensors:SC radar JQC series sonar KRemarks:Also known as Craven class. Built by Bethlehem yards, wereoriginally to be identical to Dunlap and Fanning . Defective stabilityplagued all units of class throughout most of their careers. It also

prevented class from being tted with 40mm. Total of 23 Mk7 and16 Mk6 or 41 Mk6/9 DC carried.Damage & Speed Breakdown:Dam Pts: 0 16 32 48 58 64Surf Speed: 38 28 19 10 0 Sinks

Annex A- Ships

Setup: Place two of the American destroyers onpicket duty, one between Savo Island and CapeEsperance, the other to the northeast of Savo Island.They are patrolling a 5-nm long track at 10 knots, andstart at the southern end. The two American heavycruisers and the other two destroyers should beplaced in column 5-10 nm southeast of Savo Island.

The Japanese are placed 10-15 nm west of Savo Is-land. Courses are shown on the scenario map. Bothformations are steaming at 15 knots. The Japanese player places his ships 14 nmfrom Savo, while the US player is 7 nm SE of theisland.


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-cas 4th jumpstart

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