RedactedNarrative: Pump out operator found vessel #1 with the engine down and the tilt switch appeared to be inoperative. A witness who is a deck hand at the yacht club stated that the operator of vessel #2 left a restaurant and her bar located at the Yacht club and was maneuvering his vessel away from the dock adjacent to vessel #1 in a stiff westerly wind. The wind pushed him down towards vessel #1. He gunned the engine with the rudder hard over causing the stern to swing rapidly into the raised engine of vessel #1. His maneuver was violet enough to cause a loud crash as the sim platform struck vessel #1's engine and caused the stern to lower allowing water to flood the boat. Witness states operator did not stop to access damage or attempt to identify himself. She notified her boss the dock manager and he contacted operator for his information. The intensity of the impact caused the vessel to be taken out of service as unseaworthy.