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 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.

Every vessel that has an engine other than an electric motor must have a fire extinguisher(s) on board. See the table below for the exact requirements. Foam, carbon dioxide, dry chemical, and halon extinguishers may be used to fight Type B fires.

Approved types of fire extinguishers are identified by the following marking on the label—“Marine Type USCG Approved”—followed by the type and size symbols and the approval number.

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. 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.

Remember—Keep bilges clean and free of trash in order to reduce the risk of fire.

Backfire Flame Arrestors

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

• Backfire flame arrestors must be:
  • In good and serviceable condition
  • U.S. Coast Guard–approved (must comply with SAE J-1928 or UL 1111 standards)
• It is illegal to have any holes in the mesh of the backfire flame arrestor.
• Periodically clean the flame arrestor(s) and check for any damage.

Ventilation Systems

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

• All gasoline-powered vessels, 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.
• If your vessel is equipped with a power ventilation system, turn it on for at least four minutes after fueling and before starting your engine. Also turn the ventilation system on anytime you are operating your vessel at less than cruising speed.
• If your vessel is not equipped with a power ventilation system (for example, a personal watercraft), open the engine compartment and sniff for gasoline fumes before starting the engine.

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.

Mufflers and Noise Level Limits

Vessel operators may not hear sound signals or voices if the engine is not adequately muffled.

• All vessel engines must be equipped with an effective muffling device or underwater exhaust.
• The noise level of any motorized vessel must not exceed these limits.
  • Stationary test limit:
    • 90 decibels for engines manufactured prior to January 1, 1991
    • 88 decibels for engines manufactured on or after January 1, 1991
  • Moving test limit as measured on the “A” scale and from a distance of 50 feet:
    • 84 decibels for engines manufactured prior to January 1, 1991
    • 82 decibels for engines manufactured on or after January 1, 1991
• It is illegal to own or operate a vessel that exceeds the decibel limit or a vessel that is equipped with a device that adjusts the muffling device.

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.