RedactedNarrative: Operator stated that a small fire was burning in a wiring harness, from the battery to the trolling motor, under the front hatch compartment. The front hatch compartment housed the battery and the gas tank.  He further stated that he grabbed the fire extinguisher that was on the boat to attempt to put out the fire.  He attempted to move the gas tank away from the flame before he used the fire extinguisher and when he pulled on the gas tank the line came off allowing gas to spray out onto the fire.  He stated that the fire then immediately engulfed the bottom of the boat. He stated that he knew there was nothing he could do so he told his wife to grab the baby and jump into the water.