RedactedNarrative: Operator was pulling into harbor when he pulled back on throttles and noticed black smoke coming from the exhaust.  His son opened the cabin door and yelled there is smoke in the cabin.  Operator put vessel in reverse to get away from the harbor entrance. He gave the wheel to a passenger.  He went down and opened engine room hatch.  A small flame on bottom of hatch.  He put that out with salt water.  No smoke or excessive heat was found in the engine room.  Smoke was coming from the electric panel door which is directly above the engine room hatch.  He sprayed the extinguisher up behind electrical panel.  7 people were offloaded onto the harbor master's vessel.   Operator stayed on board to try and find source of fire until the smoke was to heavy to breathe.  He jumped on a boat about 25 feet off his stern.  Vessel was dragged by it's anchor to beach by harbor master and town fire department was on scene.  Fire eventually burned out.