UNIT 1 BACKED AWAY FROM ITS DOCK AND PUT IT INTO FORWARD GEAR. IMMEDIATELY THE ENGINE MADE A LOUD "BANG" AND FLAMES EMERGED FROM UNDER THE COWLING. EVEN AFTER A B-1 FIRE EXTINGUISHER WAS USED, FIRE STILL ENVELOPED THE VESSEL. THE BOAT AND ALL UTS EQUIPMENT WAS DESTROYED. ALL OCCUPANTS GOT OFF UNINJURED.