RedactedNarrative: Operator got underway and proceeded over to the gas dock inside Saquatucket Harbor but the gas dock was not open.  He thought he had enough gas to complete his first sea trial of his boat since having engine work completed over the past winter.  Approximately 1/4 mile outside the harbor he smelled something burning.  He stated the boat never exceeded headway speed.  He looked towards the stern of the boat and observed fingers of flames coming out of the seams of the engine deck.  He stopped the boat and grabbed a fire extinguisher and then touched the handle of the engine cover which revealed it was too hot to touch and open.  He hailed for help over his VHF radio.  The smoke became over powering, so he made his attempt to get up wind of the smoke and stand on the bow of his boat awaiting help.  A very short time later the assistant harbor master arrived on scene and removed the injured  victim from the burning vessel.  