A malfunction in the Royal Majesty cruise ship's electronic navigation system caused the ship to run aground ten miles off Nantucket Island in June.

The grounding, in which 1,509 passengers and crew bound from St. George's to Boston were rescued without injury, resulted in the ship being taken off the Boston-Bermuda run for two weeks for repairs.

The Associated Press reported yesterday that the US National Transportation Safety Board said the ship drifted 17 miles off course because of a malfunction in the ship's electronic navigation system, which was steering the ship automatically along a planned route with the precise position data coming from a system of satellites.

The NTSB said it fears the system on other ships may also fail and has now called on the US Coast Guard and maritime groups to examine what problems that might cause.

The NTSB said the incident has brought to light a significant safety concern that may affect hundreds of other ships and tankers "with serious risk to life, property and the environment''.

The navigation system automatically shifted to data provided onboard -- for example, time, speed and heading -- to determine the route of the vessel. This data, however, does not account for wind current or sea conditions, causing the ship to go off course and become grounded.

Displays on the bridge still indicated that the vessel was on the correct course, so the crew was unaware of the problem, the safety board said.

The board sent letters to the US Coast Guard and to various maritime industry groups urging them "to review the design of their navigation system to determine the effects of potential system failures''.

The letters were sent the International Tanker Owners Association, the International Council of Cruise Lines, the International Chamber of Shipping, the American Institute of Merchant Shipping, and the National Marine Electronics Association as well as to the manufacturer of the Royal Majesty's navigation system.