Boat Fire Extinguisher Requirements

The law requires that a vessel must carry at least one Type B USCG-approved fire extinguisher on board if it has an engine and one of the following items.

  • A closed compartment where portable fuel tanks may be stored
  • A double bottom that is not sealed and is not filled with flotation materials
  • Closed living spaces
  • Permanently installed fuel tanks
  • An inboard engine

Although the vessels specified above are the only ones required by law to carry a fire extinguisher on board, it is recommended that all vessels carry a fire extinguisher that is easily accessible. The best location is within arm’s reach of the captain and passengers.

What types of fire extinguishers are required on which vessels? Use the chart below to determine the type and quantity needed for your vessel

Length of VesselWithout Fixed SystemWith Fixed System*
less than 26 feetone 5-Bnone
26 feet to less than 40 feettwo 5-B or one 20-Bone 5-B
40 feet to less than 65 feetthree 5-B or one 20-B and one 5-Btwo 5-B or one 20-B
* refers to a permanently installed fire extinguisher system

For carriage requirements, one 5-B is equivalent to one B-I, and one 20-B is equivalent to one B-II.

Fire Extinguisher Classifications

Fires are classified based on their source of fuel: solid, liquid, or electrical. Because these fires burn differently, they require different types of extinguishers. Extinguishers are marked as A, B, or C to indicate the class of fire they are meant to extinguish.

Fire Types

  • Type A: Made of combustible solid-fuel sources such as wood and paper. Water and Type A fire extinguishers are used to put out this type of fire.
  • Type B: Made of flammable liquid-fuel sources like gasoline. Water will only spread this type of fire. Only Type B fire extinguishers should be used on this type of fire.
  • Class C: Electrical fires. Water should never be used on this type of fire; only a Type C extinguisher should be used.

Gasoline or Type B fires are the most common types of boat fires, which is why marine-rated Type B fire extinguishers are required for most boats. The number following the extinguisher class indicates the capacity of the extinguisher.

Type ABC fire extinguishers can handle all fire types; that is why they are the most recommended class of extinguisher.

Boat Fire Extinguisher Maintenance

Fire extinguishers stored on your vessel should be inspected monthly. The following steps should be included in the monthly inspection.

  • Check to ensure the gauge is fully charged.
  • Check the seals to ensure they are not broken.
  • Inspect the hose to ensure it is not cracked or broken; replace it if it is not in good condition.
  • Weigh your dry chemical extinguishers to make sure they meet minimum weight specified.
ClassificationFoam (gal.)CO2 (lb.)Dry Chem (lb.)

You should also read:

Boating Terminology

Parts of a Boat