RedactedNarrative: VESSEL ONE WAS ATTEMPTING TO LEAVE A SLIP AT THE MARINA  AND HAD BACKED OUT OF A SLIP WHEN THE OPERATOR ACCIDENTLY HIT THE STARBOARD THROTTLE (TWIN MOTORS) WITH HIS ELBOW WHICH CAUSED THE VESSEL TO COLLIDE WITH THE SLIP WALKWAY AT SPACE.  AS A RESULT OF THE COLLISION THE MAIN WALKWAY ON "L" DOCK BECAME MISALIGNED, THE SLIP SUSTAINED DAMAGE, AND WATER MAIN ON SHORE WAS FOUND TO HAVE BROKEN NEAR THE "I" DOCK CAUSING EROSION.  VESSEL ONE SUSTAINED DAMAGE TO THE CENTER TRITOON WHICH WAS COMPLETELY CAVED INWARDS.