RedactedNarrative: Vessel 2 was unoccupied and docked in a courtesy slip at sixshooter marina. Vessel 1 operator attempted to dock vessel 1 in the courtesy slip on the north side of vessel 2.  Vessel 1 bow struck vessel 2 in the stern. Vessel 2 was pushed forward and struck the dock.  Operator of vessel 1 stated that he moved the throttle forward but the vessel did not move so he moved the throttle a little further and the vessel accelerated forward, striking vessel 2.  Owner of vessel 1 stated vessel 1 had been recently worked on for throttle issues.  Area of the accident was approx 130 feet ne of the southwest parking lot shoreline and approx 416 ft sw of the ne shoreline and approx 43 feet southeast marina southeast boat docks.