What happened
During a local area Title 14 CFR Part 91 proficiency and instructional flight, two certificated flight instructors were operating a float-equipped airplane. After completing a landing at a lake, the second pilot practiced performing step turns. The first pilot, seated in the right seat, took control of the aircraft to demonstrate continuous water taxiing and turning while on-step.
The pilot taxied around the perimeter of the lake and initiated a right turn while remaining on-step. During this maneuver, the aircraft failed to respond as expected. Despite the application of right rudder, the airplane continued its course and collided with the lakeshore and trees. The aircraft sustained damage to the left wing and fuselage, and there were no injuries reported.
At the time of the accident, the pilot reported wind conditions of approximately 6 knots from the north-northeast. However, the pilot noted that the aircraft may have encountered wind shear at the narrowest portion of the lake where the collision occurred.