The Navigators Group, Inc.“Insuring a World in Motion”

Credit Suisse First BostonAnnual Insurance ConferenceNovember 16, 2005

Stanley A. Galanski, President & CEOPaul J. Malvasio, EVP & CFO

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Forward Looking Statements

This presentation contains forward-looking statements that are subject to risks and uncertainties. All statements other than statements of historical fact included in this presentation are forward-looking statements. Forward-looking statements give our current expectations and projections relating to our financial condition, results of operations, plans, objectives, future performance and business. You can identify forward-looking statements by the fact that they do not relate strictly to historical or current facts. These statements may include words such as "anticipate," "estimate," "expect," "project," "plan,“ "intend," "believe" and other words and terms of similar meaning in connection with any discussion of the timing or nature of future operating or financial performance or other events. These forward-looking statements are based on assumptions that we have made in light of our industry experience and on our perceptions of historical trends, current conditions, expected future developments and other factors we believe are appropriate under the circumstances. As you consider this presentation, you should understand that these statements are not guarantees of performance or results. They involve risks, uncertainties (some of which are beyond our control) and assumptions. Although we believe that these forward-looking statements are based on reasonable assumptions, you should be aware that many factors could affect our actual financial results and cause them to differ materially from those anticipated in the forward-looking statements.

Because of these factors, we caution that you should not place undue reliance on any of our forward-looking statements. Further, any forward-looking statement speaks only as of the date on which it is made. New risks and uncertainties arise from time to time, and it is impossible for us to predict those events or how they may affect us. Except as required by law, we have no duty to, and do not intend to, update or revise the forward-looking statements in this presentation after the date of this presentation.

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Navigators – Investment Highlights

I. A global leader in marine insuranceMarine Insurance Pool formed in 1974 (Navigators Insurance Company)Lloyd’s Syndicate 1221 acquired in 1998. Well positioned to capitalize on post-Katrina/Rita opportunity in ocean marine

II. A track record of “hard market” growth and profitability3 year 25% compound annual Gross Written Premium growth rate (2002-2004)One of Fortune’s 100 fastest growing companies (2003 and 2004)Imbedded growth by retaining more profitable business net in 2006

III. Successful implementation of diversification strategySpecialty Property & Casualty product and geographic expansionProfessional Liability growing and profitablePortfolio diversification for stronger earnings stream

IV. A strong and leveragable platformRated “A” by A.M. Best and Standard and Poor’sLloyd’s licenses provide access to major world marketsDeep, experienced management teamNo debt

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“KatRita” Impact to Marine Market

Top 10 Marine/Energy Estimated Industry Losses (1970 – 2005)

$0

$1

$2

$3

$4

$5

$6

HurricaneKatrina

HurricaneIvan

HurricaneRita

Piper Alpha

HurricaneAndrew

Petrobras P-36

HurricaneFrances

DiamondPrincess

Pride ofAmerica

HurricaneCharley

Minimum Loss Possible Loss Maximum Loss

$0.2$0.2$0.3$0.4$0.5

$0.8

$1.5

$1.5 - $3.0

$3.0 - $5.0

$3.3

($ in billions)

8/25/05 9/2/04 9/21/05 7/6/88 8/23/92 3/20/01 9/5/04 10/1/02 1/14/04 8/11/04

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Hurricane Rita – The Knock-out Punch

Interior department reported October 3 that Rita inflicted substantially more damage to offshore oil and gas facilities in the Gulf than Katrina

2,900 of the Gulf’s 4,000 oil and gas production platforms were in the path of the two hurricanes

Rita destroyed 63 platforms and one jack-up rig

Katrina destroyed 46 platforms and four drilling rigs

Damage to onshore processing facilities may delay offshore production, leading to sizeable “contingent” business interruption losses

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“KatRita” Impact to Navigators

Navigators has a substantial excess of loss reinsurance program that limits the Company’s exposure to catastrophic claims

Net after-tax loss estimated at $15 million for Katrina and $9 million for Rita

Navigators underwriters declined to insure several of the “high-profile”accounts with major losses, thereby beating the industry result

While absorbing two of the largest marine market catastrophe losses ever in the third quarter, we expect to make a profit for the full year

A.M. Best to re-affirmed “A” rating and upgrade outlook

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The Navigators Opportunity

Hurricanes Katrina and Rita have devastated offshore energy underwriters, wiping out three to four years worth of industry premiumWe anticipate Gulf of Mexico exposures will receive rate increases of 100% or more for all accounts; those with losses will pay substantially moreWe anticipate overall marine rate levels to increase at least 10% in 2006We suspect a number of underwriters will exit the offshore energy sector altogetherWe expect the level of losses experienced by the industry in Rita and Katrina to stabilize pricing across all lines of business

Lloyd’s Marine & EnergyI. A global leader in marine insurance:

Navigators Marine & Energy

Largest and longest standing area of specialization (since 1974)Dual underwriting units through insurance company and Lloyd’s SyndicateNavigators Insurance Company will increase its participation in marine pool on January 1, 2006Navigators will provide 100% of the capacity of Syndicate 1221 beginning with 2006Regional offices in London and Houston access global energy insurance marketplace; emerging as a London company market leader in offshore energy2005 nine month combined ratios excluding storm losses for Navigators Insurance Company and Lloyd’s Syndicate 1221 were 90.0% and 90.9%, respectively

GWP ($377 million)63% of 2005 Nine Month Total

Marine & Energy (Lloyd's)

Navigators Pro

Navigators Specialty

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NWP ($167 million)55% of 2005 Nine Month Total*

*excludes reinstatement premiumsMarine & Energy (Lloyd's)

Navigators Pro

Navigators Specialty

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Marine & Energy – Mix of Business 2005

Transport6%

Cargo24%

Liability25%

Offshore Energy17%

Onshore2%

Craft/Fishing Vessel

3%P&I3%

War2%

Bluewater Hull7%

Reinsurance5%

Engineering6%

YTD June 2005 Gross Written Premium – $377 million(Consolidated total – Insurance Company and Lloyd’s)

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Marine & Energy Cumulative Rate Increases

59.0%

49.5%

24.5%

17.8%

37.0%

42.0%

42.0%

33.7%

45.5%

44.1%

41.4%

56.2%

39.3%

19.1%

39.0%

25.9%

48.2%

32.5%

32.7%

29.7%

0%

10%

20%

30%

40%

50%

60%

70%

12/31/2001 12/31/2002 12/31/2003 12/31/2004 9/30/2005

Marine Liability Offshore Energy Hull Transport Cargo

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II. A track record of “hard market” growth:

Growth and Portfolio Diversification

6 Month Growth 17%

$0

$100

$200

$300

$400

$500

$600

$700

9 Months 2005 9 Months 2004

Gross Premium Written by Segment($’s in millions)

3 Yr CAGR 25%

$0

$200

$400

$600

$800

Year 2004* Year 2003 Year 2002

11%

26%

33%

30%

$509

$595

9%

22%

37%

32%

5%26%

29%

40%

$607

$448

10%

22%

38%

30%

$696

10%

22%

37%

31%

*Includes $38.1 million RITC transaction

Navigators Agencies Marine & Energy Lloyd's Syndicate Specialty Navigators Pro

Lloyd’s Marine & Energy

III. Successful implementation of diversification strategy:

Navigators Specialty

Marine & Energy (Lloyd's)

Navigators Pro

Navigators Specialty

Marine & Energy (Lloyd's)

Navigators Pro

Navigators Specialty

GWP ($153 million) NWP ($108 million)26% of 2005 Nine Month Total 36% of 2005 Nine Month Total

Since 1995 has underwritten general liability insurance for small general and artisan contractors, mostly in California

Written on a non-admitted basisSuccessfully achieved a reduction in policy count and exposures while growing premium substantiallyAttractive pricing environment following rate increase of 30% in 2002, 49% in 2003, 13% in 2004 with a 1% rate decline in 2005 nine month period

Strategy to diversify by product line and geographically generated approximately 36% of 2005 nine month Specialty GWP compared to 26% for the 2004 year

Midwest branch operation since 2002Personal umbrella

Launched new product line, Excess Casualty in 20052005 nine month combined ratio of 91.3%Retaining more of the premium net in 2005 by elimination of quota share reinsurance

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Navigators Specialty

4,489 4,755

8,995

512 6331,009 1,022 1,231

2,035

-

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

Small Artisan Commercial GC Residential GC

Year 2004 Year 2003 Year 2002

In Force Policy CountsExposure Management Strategy – Dramatic Reduction in IFC

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Navigators Specialty – Mix of Business

Excess Casualty12%

Other2%

California Construction

64%

Personal Umbrella12%

Chicago Admitted Specialty

10%

2005 YTD Gross Written Premium – $153 Million

Lloyd’s Marine & Energy

Introduced D&O liability insurance in late 2001 with team of experienced professionalsTargeting small cap to mid cap public corporations and private companiesIn late 2002, introduced lawyers professional liability and other miscellaneous professional liability coveragesCommenced writing professional liability coverage for architects and engineers in 2005Mostly all claims made policies – reserves are substantially IBNRAs we have grown comfortable with the quality of underwriting, we have increased our net retention through a variable quota shareEstablished a London Branch presence in 2004; expanded to utilize Lloyd’s licenses in 20052005 nine month combined ratio of 98.0%

GWP ($65 million)11% of 2005 Nine Month Total

III. Successful implementation of diversification strategy:

Navigators Pro

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NWP ($26 million)9% of 2005 Nine Month Total

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Navigators Pro - Premium Distribution

Lawyers Professional

29%

Architects & Engineers

9%

Public Company D&O48%

Private CompanyD&O13%

Other1%

2005 YTD Gross Written Premium – $65 Million

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Senior management team has an average of approximately 28 years in the industry and 10 years at NAVG.

Executive

Position

Years in Industry

Terence N. Deeks Chairman 48 Stanley A. Galanski President and CEO 25 Paul Malvasio EVP, CFO 35 David E. Hope President − Navigators Marine & Energy 24 Michael L. Civisca SVP Navigators U.S. Marine & Energy 24 Noel Higgitt President − Navigators Specialty 49 Christopher C. Duca Elliot Orol

President − Navigators Pro SVP, General Counsel

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Jane Keller SVP, Chief Claims Officer 14

IV. A strong and leveragable platform:

Deep, Experienced Management Team

Lloyd’s Marine & EnergyHigh Quality Investment Portfolio

U.S. Treasury Bonds,

GNMA's & Agencies

24.3%

Municipal Bonds20.8%

Mortgage and Asset Backed

Securities25.4%

Corporate Bonds13.0%

Equities2.0%

Cash & Short-Term Securities

14.5%Invested Assets: $1.0 billionFixed Maturities and Cash:

98.0% of portfolioAverage AA ratingDuration of approximately 4.0 yearsAverage yield of 3.8% for 3Q ‘05

Equity Securities: 2.0% of portfolio

At September 30, 2005

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Hurricanes Net Loss Impact

($ in millions)

(1) Impact on 2005 and 2004 third quarter was 47.2% and 6.5% respectively(2) Impact on 2005 and 2004 third quarter was $1.87 and $.26 respectively

"KatRita" Ivan2005 2004

9 Months 9 Months

Reinstatement premiums 14.5$ 2.3$ Losses incurred 22.3 2.9Pre-tax underwriting loss 36.8$ 5.2$

Combined ratio (1) 14.9% 2.2%

Net loss - amount 23.9$ 3.4$ - per share (2) 1.86$ 0.26$

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Key Summary Financial Data

($ in millions)

(1) Excludes Hurricanes effects for both periods

20059 Months

20049 Months Change

Gross written premium $595 $509 17%

Net written premium $286 $236 22%

Net investment income $26 $19 33%

Combined ratio (1) 90.7% 88.2%

Cash flow $168 $142 18%

Adjusted net income (1) $2.50 $2.18 15%

ROE (beginning book value) (1) 13.0% 12.8%

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The Navigators’ Story

Proven track record and commitment to underwriting profit

Recent new capital will be deployed immediately toward profitable growth, rather than to fill a hole in the balance sheet

“Once in a career” opportunity in the offshore energy sector

Global leader in marine insurance with the know-how and market presence to capitalize on the immediate market opportunity in ocean marine

Expected continued satisfactory market conditions in Specialty and Professional Liability lines

Opportunity to retain more existing business net

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Navigators“Insuring a World in Motion”

Navigators“Insuring a World in Motion”