What happened
On August 25, 1999, a certificated commercial pilot was attempting to take off from a lake characterized by 2-foot tall, rolling swells. During the takeoff roll, before the aircraft had reached a safe flying airspeed, the floats struck a large wave. This impact caused the airplane to lift off the water prematurely.
The pilot reported that the left wing stalled before any corrective action could be taken, resulting in a collision with the water. The force of the impact tore the floats from the aircraft, and the plane subsequently sank. The aircraft sustained substantial damage to its wings, empennage, and fuselage.
At 0553, an Aviation Routine Weather Report (METAR) from the nearby Iliamna station indicated winds from 259 degrees at 7 knots, visibility of 10 statute miles, and broken clouds at 7,500 feet. The temperature was 51 degrees F with a dew point of 46 degrees F. Official civil twilight for the area was scheduled for 0610.