On July 1, 1994, about 1800, Atlantic standard time, N4287L, a homebuilt, Quicksilver GT-500, registered to the pilot Eduardo Castellanos, crashed in the water adjacent to Palmas Del Mar, Puerto Rico, while on a 14 CFR Part 91 flight. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The recreational certificated pilot received fatal injuries, the passenger received minor injuries, and the airplane was destroyed. The flight had originated from a local airport about 15 minutes earlier. Witnesses and the passenger stated that the pilot was flying about 20 feet above the water along the beach and was attempting to point out an apartment to the passenger. The pilot stated he would slow the airplane down and he added flaps. The passenger observed the nose pitch down and the airplane collided with the water and sank. The passenger stated he released his shoulder harness and seatbelt and swam to the surface for air. He attempted to dive to release the pilot twice but could not do so. The passenger was then assisted to the shore by surfers in the area. Examination of the airplane, engine, and controls by the FAA inspector revealed no evidence of preimpact failures.