Warby set the current record in 1978. 317.6 mph.
There's only been two official attempts to break it since.
Lee Taylor tried to get the record back in 1980. Taylor built a rocket-powered boat, Discovery II, 40-foot long reverse three-point design. Doing a test run, at 270 mph, Discovery II hit a swell and the front of the boat collapsed causing the boat to crash. It took three days to recover Lee's body in the cockpit.
Then, in 1989, Craig Arfons, nephew of Art Arfons, tried for the record in his Rain X Challenger, but he was killed when the boat flipped at 301.875 mph.
Not a record I'd have the balls to try for......