Speedboat pilot Lee Taylor's attempt to set a world water speed record ended in disaster yesterday when his rocket-powered boat disintegrated in the middle of a high-speed run at Lake Tahoe, Nev.

Douglas County Sheriff's Department Sgt. Doug Struthers said there was no trace of Taylor, although his helmet and three sections of the boat were recovered.

"Let's just say it don't look too good," Struthers said when asked about Taylor's chances for survival. "The boat disintegrated. He had no breathing apparatus. The lake is cold. It don't look too promising."

Struthers said he had been told the boat was traveling at about 360 mph when the accident occurred shortly after 2 p.m. Washington time.

A witness said Taylor's Discovery II was about 10 seconds into its attempt to break the record when the engine cut off and there was a puff of smoke. The witness said the boat veered off to one side and disintegrated.

Another witness, aboard a cruise ship, said Taylor had completed one high-speed run and was slowing when the 40-foot aluminum boat hit some waves.

Taylor, 45, of Bellflower, Calif., tested the boat Wednesday and reported that the hull of the $2.5 million creation had been dented by choppy waves on the lake.

He was aiming for the 317.6 mph record set in 1978 by Australian Ken Warby. Taylor had held the mark for 11 years before that.

The aluminum-hulled boat was the first to be powered by a 16,000-horsepower rocket designed for aircraft and missiles. It was fueled by 1,000 pounds of hydrogen peroxide.