What happened
A commercial certificated pilot was performing a landing on a gravel runway in a tundra tire equipped airplane. During the landing roll, just before the tailwheel made contact with the runway, a wind gust pushed the tail of the aircraft to the right. A subsequent gust pushed the tail to the left.
Unable to maintain directional control, the pilot applied engine power in an attempt to abort the landing. This maneuver caused the airplane to veer to the left, resulting in the left main wheel contacting the surface of a tidal slough. The right wing then struck the water, causing the aircraft to invert in approximately five feet of water. Both occupants were not injured and successfully exited the aircraft from underwater. The aircraft sustained damage to both wings and the propeller.