What happened
During the final phase of flight, the pilot was conducting an approach toward a gravel bar landing site. While maneuvering for touchdown, the pilot misjudged the descent path relative to the intended touchdown zone. Consequently, the main wheels of the aircraft contacted water and soft sand located just short of the gravel bar surface.
The impact caused the airplane to nose over, bringing it to rest in an inverted position. As a result of this sequence, the rudder sustained substantial damage. No further details regarding injuries or specific aircraft registration were provided in the source material.
The investigation
The available factual narrative indicates that the primary mechanical outcome was the substantial damage to the rudder. This damage occurred as a direct consequence of the aircraft nosing over and coming to rest inverted after the initial contact with the water and soft sand.