On April 29, 2000, about 1100 Alaska daylight time, a tundra tire equipped Piper PA-18 airplane, N4418Z, sustained substantial damage during landing at Seldovia, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight, when the accident occurred. The airplane was operated by the pilot. The commercial certificated pilot, and the sole passenger received minor injuries. Visual meteorological conditions prevailed. The flight originated at Merrill Field, Anchorage, Alaska, about 0935. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on April 29, 2000, the pilot reported he was landing on runway 16 at Seldovia. He said the wind was reported as light and variable. During the landing roll, just before the tailwheel touched the runway, a wind gust pushed the tail of the airplane to the right. A second gust of wind then pushed the tail to the left. The pilot said he was unable to fully control the direction of the airplane, and decided to add engine power and abort the landing. The airplane veered to the left and the left main wheel contacted the surface of a tidal slough. The right wing then struck the surface of the slough, and the airplane inverted in about five feet of water. Both occupants exited the airplane from underwater. The airplane received damage to both wings and the propeller. At 1053, an Automated Weather Observation System (AWOS) at Seldovia was reporting, in part: Wind, variable at 5 knots; visibility, 10 statute miles; clouds and sky condition, 6,500 feet scattered; temperature, 43 degrees F; dew point, 35 degrees F; altimeter, 29.57 inHg.