RedactedNarrative: On 09/19/15 around 15:15 hrs, the operator of the 50' vessel Seven Joys III, Operator1 was undocking from Key Largo Harbor Marina.  Once undocked he lost power on one engine, the strong wind pushed his vessel sideways in the canal. While Operator was trying to avoid a collision with the sailing vessel docked on the marina wall Operator caused his vessel's bow to collide  into a floating davit across the canal, then while trying to maneuver out of his tight spot he collided his vessel stern into the sailing vessel Calypso Poet's mid starboard side. Operator once able to correct his course left the scene, however he did indicate to a witness that he was returning once he was able to correct his mechanical failure.
  
  Upon my arrival to the entrance of Port Largo canal I encountered the Seven Joys III just outside the channel.  Operator had the engine hatches open and he appeared to be working on something mechanical.  He advised he had collided twice due to a mechanical failure. He also advised a hose had come undone causing the engine to fail.  Once the engine failure was corrected Operator operated his vessel back to his slip at Key Largo Harbor Marina, and I followed him there.
  
  Once at the Marina I met with the owner of the floating davit at 515 Caribbean Blvd and the owner of the sailing vessel Calypso Poet. We inspected the damages on the floating davit with the owner and Operator.  I observed damaged to the starboard  floating pantoon and to the harness that ties the floating davit to the seawall.  The easterly tie-down was damaged on the collision.  I estimated around $1,000.  The damages to the sailing vessel Calypso Poet was estimated around $1,500.  Operator indicated he was responsible and was willing to work things out with both owners reference the repairs. 
  
  This boating accident was caused by a mechanical failure and inexperience of Operator operating a large vessel in a congested and narrow channel.  Operator was warned about safety procedures, radio procedures, and for operating an unregistered vessel. Operator was in possesion of a temporary USCG Documented number. The vessel Seven Joys III was recently overhauled and the owner was conducting a sea trial.