RedactedNarrative: A NH state Marine Patrol Officer was on patrol when he detected an odor of burning plastic. He inspected his vessel and determined it was not coming from his but most likely the vessel in front of him. A few minutes went by and the vessel in front of the officer slowed down and came to a stop in front of a marina. The operator opened the engine compartment to expose a large plume of white smoke. As the officer came up along side the vessel the operator was discharging his fire extinguisher in the engine compartment. The vessel was then towed to a local marina where the local fire department deemed the cause of the fire was from a faulty water line used to cool the engine.