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.

All motorboats should carry an approved fire extinguisher. Both state and federal laws require fire extinguishers on motorboats carrying or using fuel or other inflammable fluid in any enclosure of the boat.

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.

Length of Vessel	Without Fixed System	With Fixed System *
Less than 26 feet	one B-I	None
26 feet to less than 40 feet	two B-I or one B-II	one B-I
40 feet to less than 65 feet	three B-I or one B-II and one B-I	two B-I or one B-II
* refers to a permanently installed fire extinguisher system

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 boat engines may backfire, all gasoline engines (except outboards) 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 must be:

In good and serviceable condition
U.S. Coast Guard–approved

Periodically clean the flame arrestor and check for any damage to the metal fins.

Ventilation Systems

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 gasoline-powered boats, 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 boat is equipped with a power ventilation system, turn it on for at least four minutes after fueling and before starting your engine.
If your boat 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.

Boats 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 and Noise

Excessive noise can prevent a boat operator from hearing signals and voices and can disturb others.

All boat engines must have a muffler, underwater exhaust, or other device that adequately suppresses the sound of the motor. It is unlawful to sell, equip, or operate a motorboat (except under permit from the county sheriff or U.S. Coast Guard) so as to exceed the noise levels below:

84 decibels on the A scale at a distance of 50 feet for engines or motorized boats built before January 1, 1982
82 decibels on the A scale at a distance of 50 feet for engines or motorized boats built on or after January 1, 1982

Equivalent readings may also be taken from other distances.

It is illegal to equip a motor with any type of cut-out.

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.