What happened
A pilot was conducting a takeoff run toward the north in a float equipped airplane on a river. The departure route involved a main channel where two branches of another river were flowing into the primary path from the right side.
During the takeoff sequence, the pilot attempted to transition the aircraft to 'on-step' by lowering the nose. At this time, the pilot raised the water rudders. A left crosswind, measured between 10 and 20 knots, was present along with a strong river current flowing from the right.
As the water rudders were raised, the aircraft veered to the left. The pilot attempted to abort the takeoff; however, the airplane failed to become airborne and subsequently collided with trees located along the left bank of the river in a shallow water area. The occupants were not injured.