RedactedNarrative: Operator advised they had just refueled. V1 was were operating near Pt. 4 on Lake Ouachita when V1 began to "act funny". The occupants stated they smelled gas so the operator shut off the motor and turned the blowers on. He then attempted to start the motor again and V1 caught on fire. All the passengers jumped out into the water and swam to shore (about 15ft).  The operator unsuccessfully attempted to put out the fire with a fire extinguisher. V1 burned to the waterline and was a complete loss.