It's the Law: Required Equipment for Your Vessel

Ventilation Systems

The purpose of ventilation systems is to remove flammable gases, greatly reducing the chance of a dangerous explosion.

• All gasoline-powered powerboats, constructed in a way that would entrap fumes, must have at least two ventilation ducts fitted with cowls to remove the fumes.
  • At least one exhaust duct must extend from the open atmosphere to the lower bilge.
  • At least one intake duct must extend from a point at least midway to the bilge or below the level of the carburetor air intake.

Backfire Flame Arrestors

Backfire flame arrestors are designed to prevent the ignition of gasoline vapors in case the engine backfires.

• All gasoline-powered motorboats, except outboards, must have a backfire flame arrestor on each carburetor that is U.S. Coast Guard–approved or stamped in compliance with SAE J-1928 or UL 1111 standards.

Mufflers and Noise Level Limits

• The exhaust of every internal combustion engine on any vessel must be effectively muffled by a muffler or underwater exhaust. That is, the engine's exhaust must be muffled or suppressed at all times so as not to create excessive noise.
• The use of cutouts is prohibited.
• It is illegal to remove or modify the exhaust or muffler system of a vessel.
• Vessels involved in a marine event authorized by the Massachusetts Environmental Police are exempt from the requirements above.