News Release   June 20 2005 OSI to showcase its world-leading submarine navigation and new command and control systems at the Undersea Defence Technology conference in Europe this week Vancouver, Canada -- Offshore Systems International Ltd. (TSX: OSI/ OTCBB: OFSYF) announced today that it will showcase its new integrated submarine navigation and weapons management system at the Undersea Defence Technology (UDT) Europe 2005 conference in Amsterdam, The Netherlands from June 21 to 23, 2005. The latest-technology SNAPS Replacement system can replace the existing, but outdated, Ship’s Navigation and Plotting System (SNAPS) on board most submarines globally. OSI is the only company developing advanced submarine functionality for three navies, including the UK’s Royal Navy, the Royal Australian Navy and the Canadian Navy. Other customers include the navies of the United States and Portugal. Currently, OSI’s submarine product is installed or under contract for installation on 25 submarines globally. OSI will host a presentation on Wednesday, June 22 at 9:30 a.m. at its booth in Hall 11, Stall Number 102. In addition to presenting the latest-technology submarine command and control system, OSI will demonstrate its world-leading submarine-version navigation system called ECPINS® - S (Electronic Chart Precise Integrated Navigation System – Submarines). ECPINS® - S is an extension of OSI’s highly mature, world-leading military technology for surface navigation, with sophisticated functionality for sub-surface navigation. OSI is one of the only companies that can provide both surface and submarine technology that meets NATO’s navigation standard for warships (WECDIS). UDT Europe 2005 states that its conference will present the latest developments in undersea defence technology. It will bring together “naval decision makers, defence scientists, technologists, and procurement specialists with the leading undersea defence manufacturers and suppliers in a forum 100% dedicated to the discussion and utilisation of the latest undersea defence technology, products and services.” For more information on the conference, please visit the UDT Europe 2005 website at www.udt-europe.com. About Offshore Systems International Limited Offshore Systems International Ltd. (OSI) is a pioneer in geospatial intelligence software and systems. The Company conducts its operations through three business units: OSI Navigation Systems (moving map display systems and software), OSI Applications (situational awareness products and services for command and control systems) and Mapcon Mapping (digital map and electronic chart data production services: land and marine). OSI’s common shares are listed for trading on the Toronto Stock Exchange (TSX: OSI) and the OTC Bulletin Board (OTCBB: OFSYF). Visit OSI’s website at www.osil.com for more information and the latest Company updates. Forward-Looking Statements This news release contains discussion of items that may constitute forward-looking statements within the meaning of securities laws including Section 27a of the Securities Act of 1933, as amended, and Section 21e of the Securities Exchange Act of 1934, as amended, with respect to achieving corporate objectives, developing additional project interests, OSI’s analysis of opportunities in the acquisition and development of various project interests and other matters. These statements are made under the ‘safe harbour’ provisions of the Private Securities Litigation Reform Act of 1995 and, as such, involve known and unknown risks and uncertainties and other factors that may cause the actual results to be materially different from the results implied herein. Although Offshore Systems International believes the expectations reflected in such forward-looking statements are based on reasonable assumptions, it can give no assurances that its expectations will be achieved. Factors that could cause actual results to differ from expectations include the effects of general economic conditions, changing foreign exchange rates, actions by government authorities, uncertainties associated with contract negotiations, and industry supply.   For more information contact: Jane Hayward Investor Relations +1 613 287 0462 or +1 888 880 9797 +1 613 287 0466 (FAX) invest@osigeospatial.com