FALL RIVER, Mass. (AP) _ Gerard Zinser's most vivid memory of the night his U.S. Navy boat was destroyed is of his commander, Lt. John F. Kennedy, saving a burned sailor by gripping the man's life jacket laces in his teeth.

Zinser is the last man alive who was aboard Patrol Torpedo Boat No. 109 the night it was rammed by a Japanese destroyer in the Pacific and cut in two. He joined other World War II veterans and relatives Monday in commemorating the 50th anniversary of that fateful night.

Zinser, of Naples, Fla., had nothing but fond memories of the boat's young skipper, who would be elected president of the United States in 1960.

''I think it's a good dedication to a great man,'' Zinser, 75, said of Monday's activities on the stern of the battleship Massachusetts.

''He had courage,'' he said of Kennedy. ''He was brave.''

''On the wall of my Senate office in Washington is a photo of my brother on PT-109,'' Sen. Edward M. Kennedy, D-Mass., told those present. ''That picture has always reminded me of Jack's courage.''

''In honor of Jack, today we honor all the veterans who served in that war,'' Kennedy said.

John F. Kennedy was credited with saving 10 members of his crew on PT-109 by leading them to an island after their boat was rammed. Two crew members were killed.

The senator said his brother ''talked with sad fondness of those who died.''

Kennedy towed Patrick ''Pappy'' McMahon, who had been badly burned, by gripping the laces of McMahon's life jacket in his teeth.

That, said Zinser, is what stands out most in his memory of that night.

Many of the survivors of PT-109 went on to campaign for their skipper when he ran for president.

But his image as a war hero did not emerge until Robert J. Donovan wrote the book ''PT-109'' in 1962. It was later made into a movie starring Cliff Robertson.

Among those at Monday's ceremony was William Byrnes, who served aboard PT- 358 in the Philippines and Borneo. He brought his young grandsons, Jeffrey and Patrick, with him.

''They'll remember this, I hope,'' said Byrnes, 62.

''I tried to instill this in my children, and now I'm trying to instill this in my grandchildren,'' he said. ''I want them to remember what this country is all about. When we're gone, who will remember?''