This world speed record for jet-boat has held for over 40 years. Until 20 November 1977 every official water speed record had been set by an American or Briton. That day Australian Ken Warby broke the Anglo-American domination when he piloted his Spirit of Australia to 464.46 km/h (288.60 mph) to beat Lee Taylor's record. Warby, who had built the craft in his back yard, used the publicity to find sponsorship to pay for improvements to the Spirit. On 8 October 1978 Warby traveled to Blowering Dam, Australia, and broke both the 480 km/h (300 mph) and 500 km/h barriers with an average speed of 511.12 km/h (317.6 mph). He became the first and only person to exceed 300 mph (482 km/h) on water and live to tell the tale. As he exited the course his peak speed as measured on a radar gun was approximately 552 km/h (345 mph).
Warby built Spirit of Australia in his backyard on a shoestring budget and had the boat ready for trials in 1974. He started the project as a Makita salesman who happened to team up with two Leading Aircraft Men at RAAF Base Richmond in the early 1970s Crandall and Cox were instrumental in installing and engineering the Westinghouse engine that was not in working order when first obtained. The Spirit was covered with a canvas tarpaulin when it rained and was made of wood and fiberglass. Warby was able to obtain the jet engine himself as military surplus; obtained from an auction for only $69. He left his job and named his quest Project 300 (after the 300 mph barrier).
Professor Tom Fink, who had worked with Donald Campbell 20 years earlier, provided technical advice on wind-tunnel tests and constant design modifications. Even the night before the attempt, Warby cut six centimeters off the rudder to reduce drag.
Warby's record still stands as of 2021. There have only been two official attempts to break it, both resulting in the death of the driver. Donald Campbell died on his attempt after his hydroplane crashed at over 320 mph.
By 2003 Warby had designed and built another vessel, which he has called Aussie Spirit, and with which he planned to increase his own record. It is of similar dimensions to Spirit of Australia and also is powered by a Westinghouse J34 jet engine. The rudder alone on this new boat cost more than the $10,000 all-up cost of the original Spirit. Again, Warby designed, built, self-financed and piloted his own boat.
In recent years, Warby has been associated with offshore power boat racing in the US with the AMF team. It was at such an event with AMF at Chattanooga, Tennessee on 16 October 2007 that he officially ran his jet-boat for the last time. On the 30th anniversary of the 1977 record, Warby announced his retirement from further record attempts.