On January 18, 2004, about 0850 Hawaiian standard time, a Scott RV-8A experimental airplane, N809RS, was ditched in the ocean following a loss of engine power, approximately 25 miles southeast of Lihue, Hawaii. The pilot was operating the airplane under the provisions of 14 CFR Part 91. The airline transport pilot, the sole occupant, was not injured; the airplane was destroyed. The inter-island personal cross-country flight departed the Honolulu International Airport (HNL), Honolulu, at 0820, destined for Lihue. Visual meteorological conditions prevailed, and no flight plan had been filed. In a written statement, the pilot reported that during the descent into Lihue, he noted a "faint rumble and then the manifold pressure and rpm reduced very smoothly." He changed fuel tanks, turned the fuel pump into the "ON" position, and "moved" the throttle. The engine was idling about 1200 rpm, the oil pressure gage indicated 40, and the fuel pressure gage was indicating normal. The pilot transmitted a "Mayday" call. He continued to troubleshoot the problem by turning the ignition to the "OFF" position, then to the "ON" position. The manifold pressure and rpm did not change. After securing the electronic locator transmitter (ELT) and a life vest, the pilot opened the canopy; the airplane was approximately 200 feet above sea level (asl). The airplane impacted the ocean at 50 knots. The airplane flipped over, with the nose positioned down at a 45-degree angle. The pilot then swam out to the tail of the airplane. The airplane sank in about 3 minutes.