RedactedNarrative: V1 WAS BEING LAUNCHED FROM THE TRAILER INTO THE WATER. WHEN OPERATOR 1 TURNED THE KEY ON A FIRE STARTED IN THE FLOOR OF V1, CAUSING THE DAMAGE. OPERATOR HAD LOADED THREE PORTABLE TANKS FULL OF FUEL ONTO THE VESSEL MINUTES BEFORE LAUNCHING THE BOAT.  THE PORTABLE TANKS WERE IN THE BACK OF THE BOAT IN THE FLOOR AREA.