On September 10, 1995, about 1000 Alaska daylight time, a float equipped Cessna 180A, N94259, sank after an aborted takeoff from Tazlina Lake, about 20 miles southwest of Glennallen, Alaska. The airplane was being operated as a visual flight rules (VFR) positioning flight under Title 14 CFR Part 91 when the accident occurred. The airplane, operated by Alaska Air Ventures, Glennallen, was destroyed. The certificated commercial pilot, the sole occupant, was not injured when the airplane inverted. Visual meteorological conditions prevailed. Company flight following procedures were in effect. The flight originated from Snowshoe Lake, about 38 miles west of Glennallen, about 0830. The operator reported that he landed on Tazlina Lake to drop off 2 hunters. The lake is fed from glacier melt water from the Tazlina glacier. Windy conditions from the glacier produced choppy waves of about 3 to 4 feet high. After dropping the hunters, the pilot taxied out on to the lake for departure. During the takeoff run, the airplane floats received several hard impacts from the waves that were washing over the top of the floats. The pilot aborted the takeoff and water taxied on the lake, looking for calmer conditions. The left float began to fill with water and the airplane rolled over. The airplane did not sink at that time. The pilot exited the airplane and climbed onto the inverted airplane floats. About 1400, the floating airplane was spotted by a passing float equipped airplane that landed to lend assistance. The pilot had developed syptoms of hypothermia. The pilot was unable to retrieve a rope from the other airplane but did manage to grab a sleeping bag. The second airplane departed to radio for more assistance. About 1545, the pilot received serious injuries during a rescue attempt and subsequent crash of a helicopter that came to the pilot's aid. The airplane sank after the rescue. The second accident is ANC-95-T-A166. The pilot did not return a pilot/operator report (NTSB form 6120.1/2) to the investigator-in-charge.