On August 13, 2004, about 1530 Alaska daylight time, a float-equipped Piper PA-18-150 airplane, N8653Y, sustained substantial damage following a loss of control and subsequent collision with the waters of Skilak Lake, about 16 miles east of Soldotna, Alaska. The airplane was being operated as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The private certificated pilot was not injured; the sole passenger sustained minor injuries. Visual meteorological conditions prevailed. The flight originated about 1525, from a private residence located on Caribou Island, located in the center of Skilak Lake, and about 3 miles from the accident site. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on August 24, the pilot reported that after departing from Caribou Island, he proceeded northwest for the short flight to the northwestern shore of Skilak Lake. He said that while maneuvering low over the water for a landing to the east, while in a right turn, the airplane stalled and collided with the surface of the lake. He added that after the collision, the airplane nosed over and partially sank. The airplane sustained substantial damage to the wings, fuselage, and empennage. The pilot noted that there were no preaccident mechanical anomalies with the airplane. The pilot reported that at the time of the accident, he estimated the winds to be out of the northwest at 10 knots.