RedactedNarrative: Vessel 1 was backing into slip and backed into vessel 2 which was docked unoccupied.  Vessel 1 struck vessel 2 with its stern port quarter and swim platform.  Vessel 2 rode up over the swim platform receiving multiple gouges and scrapes to the hull.  Vessel was additional pushed into the dock causing damage to the port quarter.  Vessel 1 sustained damage to its swim platform and stern port quarter.  Two docks in the marina were also deformed.  Operator of vessel 1 was under the influence of alcohol at the time of the accident.