On October 3, 2000, at 0815 eastern daylight time, a Joseph A. Grimaud Seawind 3000 experimental amphibious airplane, N98GG, was substantially damaged when it collided with ground following a loss of engine power during climb out shortly after departure from Lake Murray in Chapin, South Carolina. The commercial pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight being conducted under Title 14 Code of Federal Regulations Part 91. The flight originated from Chapin, South Carolina, at 0800. According to the pilot, he performed a preflight inspection of the airplane the previous evening. The fuel gauges indicated 7 and 4.5 gallons in the left and right auxiliary tanks, respectively, and 32 and 17 gallons in the left and right main fuel tanks, respectively, to which he visually confirmed. In addition, he added two quarts of oil to an existing 10 quarts. Prior to departure from the lake, he performed a check of the magnetos, with a drop of 75 rpm each. According to the pilot, all engine readings were normal. Following departure from the lake, he turned on course and initiated a climb in anticipation of reaching a cruise altitude of 6,500 feet. He reduced the power to 25 inches of manifold pressure and 2,500 rpm, and adjusted the fuel mixture to obtain a fuel flow of 20 gallons per hour. At that time, all engine instruments were within normal operating ranges. He selected the auxiliary fuel pump in order to drain the remaining fuel from the auxiliary tanks into the main fuel tanks. He also selected the fuel transfer pump to transfer fuel from the left main tank to the right main tank. Several minutes later, the auxiliary tanks were indicating empty and he turned the auxiliary transfer pump off. According to the pilot, as the airplane climbed through 3,000 feet, he began to perform a visual check of the main fuel tanks. The right fuel tank indicated 27 gallons and as he was preparing to check the left tank's fuel status (only the left or right fuel tank can be read at one time), the engine quit. He stated that the engine "wavered once or twice and quit." He confirmed that the main fuel boost pump was on, then checked the main fuel shut-off and confirmed that it was open/in. After selecting a forced landing area, the pilot applied full rich mixture and initiated a forced landing in a cow pasture. While maneuvering for the landing, the airplane collided with trees short of the pasture. The examination of the airplane disclosed that the fuel tanks were compromised, and the amount of fuel on board the airplane at the time of the accident was not determined. All associated fuel vents were clear of debris. The electric fuel pump and the magnetos were functionally tested, and no abnormalities were detected. The engine was test run, and no discrepancies were observed.