RedactedNarrative: On September 8, 2023, at approximately 3:15 PM, I Sergeant of the Maryland Natural Resources Police responded to a reported vessel fire on the main stem of the Severn River in Anne Arundel County, Maryland. While en route on my patrol vessel, I overheard on Marine VHF Radio Channel 16 that the reported fire had been extinguished. I arrived at the scene at approximately 3:30 PM and saw the dark blue and white 1996 Cobalt 220 open motorboat bearing registration drifting near a United States Coast Guard vessel and two vessels from the Annapolis Harbormasters Office. The location was near the channel marker buoy #8. Upon my arrival, no smoke or fire was coming from the Cobalt and I did not see any apparent fire burn damage on the vessel's exterior. Two passengers and one dog were onboard the Cobalt at the time of the incident, and they were transferred to an Annapolis Harbormaster vessel before my arrival. They were the owner/operator of the Cobalt and passenger/
  
  I asked what occurred, and they told me that Operator1 was operating the vessel, cruising at approximately 20-25 mph going up the main stem of the Severn River. Heavy white smoke appeared from the engine compartment and Operator1 then brought the vessel to a stop and turned the engine off.
  
   Occupant grabbed the onboard fire extinguisher and discharged it into the engine compartment which successfully stopped any further smoking. Both donned personal flotation devices and called for help using the onboard marine VHF radio. Operator1 told me that his vessel was recently re-powered with a brand-new Michigan Motorz 330 horsepower engine that was installed at South River Marina.
  
  I took photos of the vessel's engine compartment and saw no apparent fire burn damage to the vessel itself. The engine was covered in white powder from the fire extinguisher discharge. 
  
  I transferred both and their dog from the Annapolis Harbormaster vessel to my vessel. Operator1 called Tow Boat U.S. to arrange a tow for his vessel. I tied the Cobalt to the side of my patrol vessel to hold the location until the tow boat arrived. At approximately 4:30 PM a Tow Boat U.S. tow boat arrived and both and their dog were transferred back onto their vessel. The tow boat towed them back to South River Marina.
  
  On September 26, 2023, Operator1 reported to me that the estimated damage to his vessel was $4,500. It was determined that the port side exhaust manifold overheated and burned rubber gaskets and o-rings, which was the source of the smoke. The port side exhaust manifold had to be replaced.
  
  All events occurred in Anne Arundel County, Maryland.
  
NameOfBodyOfWater: Severn River- Main Stem
NearestCityTown: Annapolis                     