RedactedNarrative: Operator stated they were traveling in Flowery Branch Creek on Lake Lanier when the vessels engine suddenly shut off.  Then he and the other occupants noticed smoke coming from the engine compartment. They tried to extinguish the fire using the fire extinguisher onboard the vessel with not luck.  A witness stopped and got all the occupants onto his vessel.  He also offer his fire extinguisher to assist with putting the flames out.  Cause of the fire is believed to be related to the electrical system.