Boat Fire Extinguisher Requirements, Classes & Maintenance


Boat Fire Extinguisher Requirements

It's time to introduce the next important piece of safety equipment on your boat: the fire extinguisher.

You are required by law to have a fire extinguisher on board if your boat has an engine and meets any of the following conditions:

  • Your boat has closed compartments where portable fuel tanks may be stored.
  • Your boat has a double bottom that is not sealed to the hull and that is not completely filled with flotation materials.
  • Your boat has closed living spaces.
  • Your boat has permanently installed fuel tanks.
  • Or if your boat has an inboard engine.

It is not required by law to carry a fire extinguisher on other types of boats but it is still highly recommended. Fires can happen unexpectedly and it’s always a smart idea to be prepared.

No matter the type of boat, to be prepared your fire extinguisher needs to be accessible.

So make sure that you mount your fire extinguisher in a location that is easy to reach in the event of an emergency. Ideally, it should be within arm’s reach of you and your passengers.

Now, let's quickly review the number of and types of fire extinguishers you need on your boat.

  • If your boat is less than 26 feet, you need one B1 fire extinguisher on board.
  • If your boat is between 26 and 40 feet, you need either two B1 or a single B2 fire extinguisher.
  • And finally, if your boat is between 40 and 65 feet, you need either three B1 extinguishers or two B2 extinguishers.

If your boat is longer than 65 feet, check the federal regulations.


Less than 26 ft.

26 ft. to less than 40 ft.

40 ft. to less than 65 ft.

Greater than 65 ft.

Must meet federal requirements

Inboard engines

When the engine compartment is equipped with a fixed (built-in) extinguishing system, one less B-1 extinguisher is required onboard.

Fire Extinguisher Classification


Fires are classed depending on their fuel source: solid, liquid or electrical. Each fire burns differently and requires a specific type of extinguisher. That's why every fire extinguisher is marked with a letter, like A, B or C. The letter indicates both the class of fire extinguisher and the class of fire it is designed to put out.

Fire Types Are:

Class A fire type illustration

CLASS A: Combustible solids

Class B fire type illustration

CLASS B: Flammable liquids

Class C fire type illustration

CLASS C: Electrical fires

Class A fires have a solid combustible fuel source like wood or paper. You can use water, or a Class A fire extinguisher, to put out this type of fire.

Class B fires, on the other hand, have a flammable liquid fuel source, like gasoline. Do not use water to put out a Class B fire as it will just spread the fire. Instead, use a Class B fire extinguisher.

Finally, a Class C fire is an electrical fire. Like a Class B fire, never use water on a Class C fire. Use a Class C fire extinguisher.

Because gasoline fires are the most common type of boat fire, marine-rated Class B fire extinguishers are the class required on most boats. The number after the B, for example a B1 or B2 extinguisher, indicates the capacity of the extinguisher.

It's important to note that you can also get fire extinguishers that put out multiple types of fires. A Class ABC fire extinguisher, which can handle all fires, is therefore the most recommended class of extinguisher.

There are different types of fire extinguishers, with the most common being a dry chemical extinguisher.

Boat Fire Extinguisher Maintenance


A monthly inspection of your boat fire extinguisher should be a part of your regular boating maintenance. This will make sure your extinguisher is always ready to go in the case of an emergency.

Include the following steps in your monthly boat fire extinguisher inspection:

  • First, check the gauge to make sure it is still fully charged.
  • Next, look at the seals to make sure they have not been broken.
  • Then inspect the hose to make sure it is not cracked or broken; and replace it if you find it’s not in good condition.
  • Last but not least, for dry chemical extinguishers, weigh your extinguisher to make sure it meets the minimum weight specified on the label.

Done! Your fire extinguisher is good to go for another month!



Foam (gal.)

CO2 (lb.)

Dry Chem (lb.)









boat fire extinguisher illustration