1 The Navigators Group, Inc. “Insuring a World in Motion” Cochran, Coronia & Co. Investor Meetings June 22, 2004 New York City Stanley A. Galanski, President & Chief Executive Officer Paul J. Malvasio, Executive Vice President & Chief Financial Officer

2 This presentation may contain “forward looking statements” as defined in the Private Securities Litigation Act of We cannot assure that results which we anticipate will be achieved, since results may differ materially because of known and unknown risks and uncertainties which we face. Please refer to Navigators’ most recent Form 10-Q and Form 10-K for a description of Navigators’ business and the important factors which may affect that business. Navigators undertakes no obligation to publicly update or revise any forward looking statement.

3 Navigators – Investment Highlights A global leader in marine insurance –Business founded through Navigators Agencies in 1974 –Lloyd’s presence through Syndicate 1221 acquired in 1998 Complements US operations and provides global market access Commitment to underwriting profit –World-class specialty underwriting teams –Emphasis on bottom-line results, not market share Diversifying opportunistically into attractive new business lines –Specialty Property & Casualty and Professional Liability –Excellent market opportunities and producer support –Portfolio diversification for stronger earnings stream across market cycles Operating from a strong and leveragable platform –Rated “A” by A.M. Best and Standard and Poor’s –Lloyd’s licenses provide access to major world markets –No debt

4 Senior underwriting management team has an average of approximately 29 years in the industry and 13 years at NAVG. Deep, Experienced Underwriting Team

5 Growth and Portfolio Diversification Gross Premium Written by Segment ($’s in millions) 6% 21% 47% 26% $196 7% 18% 44% 31% $175 9% 22% 37% 32% 5% 26% 29% 40% $607 $448

6 Navigators Marine & Energy Largest and longest standing area of specialization for over 30 years Navigators has an 80% participation in marine insurance pool operated by Navigators Agencies in 2003 and 2004 Renewal rate increases averaged 4% in first quarter 2004, 13% in 2003, and 21% in 2002 Every regional office produced an underwriting profit in 2003 (excluding asbestos reserve strengthening) First quarter 2004 combined ratio of 86.4% 30% of 2003 Year NWP 26% of First Quarter 2004 NWP

7 Marine & Energy - Mix of Business % 12% 9% 10% 20% 4% 7%

8 Marine & Energy – Rate Increases

U.S. Market Share ($ in thousands) Note: As reported by the AIMU.

10 Lloyd’s Marine & Energy Navigators Underwriting Agency, Ltd. manages Syndicate 1221 Navigators provides 97.4% of Syndicate 1221’s gross capacity / $255mm for 2004 underwriting year compared to $200mm for 2003 A Lloyd’s market leader in cargo and specie insurance Millennium Consortium at Lloyd’s for construction/engineering risks Expansion of Pennine operations positioned in three regional U.K. offices Renewal rate increases averaged 4% in first quarter 2004, 15% in year 2003 and 26% in year 2002 First quarter 2004 combined ratio of 84.9% 37% of 2003 Year NPW 47% of First Quarter 2004 NPW

Lloyd’s Market Share (₤ in thousands) Source: Lloyd’s Market Association

12 Lloyd’s Marine Premium Rates % Base Year = 1992

13 Navigators Specialty Since 1995 has underwritten general liability insurance for small general and artisan contractors, mostly in California –Written on a non-admitted basis –Instituted a premium “cap” of $100 million GWP in 2003 –Achieved rate increases of 28% in the first quarter of 2004 on top of 49% in 2003 and 30% in 2002, resulting in substantially reduced exposure and adequate pricing Strategy to diversify by product line and geographically generated approximately 20% of 2003 Specialty GWP –Midwest branch operation since 2002 –Personal umbrella –Surety First quarter 2004 combined ratio of 98.8% 28% of 2003 Year NWP 21% of First Quarter 2004 NWP

14 Navigators Specialty Exposure Management Strategy – Dramatic Reduction in IFC In Force Policy Counts

15 Navigators Pro Introduced D&O liability insurance in late 2001 with team of experienced professionals In late 2002, introduced lawyers professional liability and other miscellaneous professional liability coverages Targeting small cap to mid cap public corporations and private companies Claims made policies – reserves are substantially IBNR As we have grown comfortable with the quality of underwriting, we have increased our net retention through a variable quota share First quarter 2004 combined ratio of 80.7% 5% of 2003 Year NWP 6% of First Quarter 2004 NWP

16 Navigators Pro - Premium Distribution $53 Million GWP 2003 ($ in millions)

17 Navigators Insurance Company High Quality Investment Portfolio Invested Assets: $726 million Fixed Maturities and Cash: –97% of portfolio –Average AA rating –Duration of approximately 3.8 years –Average yield of 3.4% for 1 st Quarter 2004 Equity Securities: 2.8% of portfolio At March 31, % 33.4% 20.3% 13.2% 10.2% 2.8%

18 Net Income and Book Value Growth Consolidated Group Data ($’s in millions) *At December 31, 2003

19 Why Navigators Now? Global leader in marine insurance Diversification strategy is on target Experienced management team Intellectual capital / specialty expertise Commitment to underwriting profit Proven track record Operating from a strong and leveragable platform

20 Navigators “Insuring a World in Motion”