Chapter 4: The Legal Requirements of Boating
Fire Extinguishers

Extinguishers are classified by a letter and number symbol. The number indicates the relative size of the extinguisher and the letter indicates the type and size of fire it will extinguish:

• Type A fires are of combustible solids like wood.
• Type B fires are of flammable liquids like gasoline or oil.
• Type C fires are electrical fires.

All vessels, including PWCs, are required to have a Type B fire extinguisher(s) on board if one or more of the following conditions exist:

• Closed compartments under seats where portable fuel tanks may be stored
• Double-bottoms not sealed to the hull or which are not completely filled with flotation material
• Closed living spaces
• Closed storage compartments where combustible or flammable material is placed
• Permanently installed fuel tanks (tanks secured so they cannot be moved in case of fire or other emergency are considered permanently installed)

Approved types of fire extinguishers are identified by the following marking on the label—“Marine Type USCG Approved”—followed by the size and type symbols and the approval number. Only USCG–approved fire extinguishers are legal for use on vessels.

Use this chart to determine the type and quantity of fire extinguishers required for your vessel.

Extinguishers should be placed in an accessible area—not near the engine or in a compartment, but where they can be reached immediately. Be sure you know how to operate them.

Fire extinguishers must be maintained in usable condition.

• Extinguishers should be serviced at least every two years. See the label for additional servicing information.
• Inspect extinguishers regularly to ensure the following.
  • Seals and tamper indicators are not broken or missing.
  • Pressure gauges or indicators read in the operable range.
  • There is no physical damage, corrosion, leakage, or clogged nozzles.

Fire Extinguisher Charge Indicators

Check the charge level of your fire extinguishers regularly. Replace them immediately if they are not fully charged.

To check this style of extinguisher, depress the green button. If it is fully charged, the green button should pop back out immediately.
On this style of fire extinguisher, the needle indicator should be in the "full" range.

Backfire Flame Arrestors

Because vessel engines may backfire, all powerboats (except outboards) fueled with gasoline must have an approved backfire flame arrestor on each carburetor. They are designed to prevent the ignition of gasoline vapors in case the engine backfires.

• Backfire flame arrestors or equivalent backfire flame protection systems must be:
  • In good and serviceable condition and...
  • U.S. Coast Guard-approved, or comply with SAE J-1928 or UL 1111 standards
• Periodically clean the flame arrestor or the equivalent backfire flame protection system and check for any damage.

Ventilation System

The importance of ventilation is crucial. The purpose of ventilation systems is to avoid explosions by removing flammable gases. Properly installed ventilation systems greatly reduce the chance of a life-threatening explosion.

• All vessels that use gasoline as their fuel with enclosed engine and/or fuel tank compartments are required to be equipped with a ventilation system.
  • Vessels built after July 31, 1980, must have a powered ventilation system consisting of one or more exhaust blowers. Each intake duct for an exhaust blower must be in the lower one-third of the compartment and above the normal accumulation of bilge water.
  • Vessels built prior to August 1, 1980, must have natural ventilation (at least two ducts fitted with cowls or intake opening from the atmosphere).
• All owners are responsible for keeping their vessel’s ventilation systems in good operating condition.
• If your vessel is equipped with a power ventilation system, turn it on for at least four minutes after fueling, before starting your engine.
• If a vessel, such as a personal watercraft, is not equipped with a power ventilation system, open the engine compartment and sniff for gasoline fumes before starting the engine.

WARNING: Gasoline vapors can explode. Before starting engine, operate blower for four minutes and check (using your nose) engine compartment for gasoline vapors. Vessels built after July 31, 1980, which contain power exhaust blowers in gasoline engine compartments, must have the above warning sticker placed near the instrument panel.

Powerboats are built to ventilate the engine when underway. As the boat moves along, an air intake scoops up fresh air and forces it down the air duct into the engine compartment. The exhaust sucks out the explosive fumes from the lowest part of the engine and fuel compartments.

Mufflers

All vessels equipped with an engine must be effectively muffled by equipment constructed and used to muffle the noise of the exhaust in a reasonable manner. Excessive noise could prevent a vessel operator from hearing signals and voices.

Vessel Safety Checks

The U.S. Coast Guard Auxiliary and U.S. Power Squadrons will perform a Vessel Safety Check (VSC) of your vessel and equipment free of charge. This inspection covers federal and state requirements. If your vessel meets all VSC requirements, you will receive a VSC decal. If your vessel fails to meet all requirements, no report is made to any law enforcement agency.