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Boat Fire Extinguisher Requirements – 2023 Updated

Written by Anthony Roberts / Fact checked by Jonathan Larson

boat fire extinguisher requirements

Fires are a threat even in the most technologically advanced watercraft, making compliance with local, state, and federal boat fire extinguisher requirements all the more crucial.

Here’s a glimpse of fire extinguisher requirements for boats.

  • You’ll need one 5B fire extinguisher if your watercraft is shorter than 26 feet.
  • You can equip your boat with one 20B fire extinguisher or two 5B types if the vessel is 26 to less than 40 feet long.
  • A 40- to 65-foot watercraft needs three 5B extinguishers or a combination of one each 5B and 20B units.

You might ask what 5B and 20B fire extinguishers are or whether other classifications and types exist. Please continue reading because we’ll give you all the information you need about marine fire extinguisher requirements.

Fire Extinguisher Regulations for Boats


The United States Coast Guard has a detailed set of rules and regulations regarding fire protection for recreational vessels. You can check the USCG fire extinguisher requirements and learn more about the specifics, including fire protection systems for large vessels.

Requirements based on boat size and type


The requirement for fire extinguishers on a boat varies across vessel sizes. As a rule, the number of fire extinguishers on any watercraft increases with boat size. Hence, a 30-foot yacht will need more fire suppression systems than a 20-foot boat.

Here’s a table describing fire extinguisher requirements based on boat size.

Boat Size

Fire Extinguisher Requirement

Boat engines with fixed fire extinguishing systems Boat engines without fixed fire extinguishing systems
<16 feet 0 1 x 5-B
16 to <26 0 1 x 5-B
26 to <40 1 x 5-B 2 x 5-B, or

1 x 20-B

40 to <65 2 x 5-B 3 x 5-B, or

1 x 20-B + 1 x 5-B

Note that vessels longer than 65 feet don’t have specific fire extinguisher requirements. However, the US Coast Guard says watercraft of at least 50 tons must have at least one 20B fire extinguisher. Here’s the other information you might need.

Vessel Weight Fire Extinguisher Requirement
<50 tons At least 1 x 20-B
50 to <100 tons At least 2 x 20-B
100 to <500 tons At least 3 x 20-B
500 to <1,000 tons At least 6 x 20-B
1,000 tons At least 8 x 20-B

We can refer to these two tables to determine how many fire extinguishers are required for a particular boat.

It’s also worth noting that boat models constructed before 2018 can choose newer fire extinguisher versions (5-B and 20-B) or legacy systems (i.e., B-II or B1 fire extinguisher).

However, owners of pre-2018 boat models must replace their old fire extinguishers (B-I and B-II) with newer models (5-B and 20-B) upon expiry.

Boat owners and operators might consider checking their state and local laws.

For example, the fire extinguisher law in North Carolina requires Class 1 and A watercraft to carry at least one B-1 portable fire extinguisher unless it has an outboard engine with an open design.

This N.C. requirement isn’t specific to the state, however. You can see similar regulations in other states, like Maryland.

So, what type of vessel is required to have fire extinguishers? Any watercraft with the following conditions must have a fire protection system.

  • Boats with inboard motor
  • Watercraft with closed accommodation or living spaces
  • Vessels with permanently mounted or fixed fuel tanks
  • Watercraft with closed spaces for storing combustible and flammable materials (i.e., fuel, paper, and wood)
  • Double-bottom boats with insufficient floatation filling and unsealed to the watercraft’s hull

Types of Fire Extinguishers Based on Type of Fire


Learning the different fire extinguisher requirements for watercraft requires understanding the type of fire extinguisher for boat units you must use for different types of fire.

  • Class A fires: Paper, wood, plastics, rubber, and other solid objects with a flash point between 100 and 200 degrees Fahrenheit can easily catch fire, making them combustible solids. A Class A or Class ABC fire extinguisher can put out this type of fire.
  • Class B fires: Flammable liquids (i.e., petroleum products and spirits) have a flash point of fewer than 100 degrees Fahrenheit, making them easier to start fires on boats.

Unfortunately, some novice boaters and crew worsen the situation by dousing the fire with water. The safety equipment you need is a Class B or Class BC extinguisher.

  • Class C fires: These fires originate from faulty electrical systems (i.e., outdated wirings, fraying, and short circuits). Modern boats have many electrical appliances, gadgets, and fixtures, making them susceptible to electrical fires. Only Class C and Class BC extinguishers can put out such fires.

Comparison of ABC, BC, and Class K Fire Extinguishers

The following table summarizes the fire extinguisher types (including how they work. It will help you determine the right kind of fire extinguisher for boat units to use on different fires.

Fire Extinguisher Class Type of Fire How they Put out Fires
Class ABC Fires due to combustible solids, flammable liquids, and energized electrical devices Monoammonium phosphate or similar dry chemicals react with the flame to create a barrier against oxygen
Class BC Fires due to flammable liquids and electrical faults Sodium bicarbonate or potassium carbonate
Class K Cooking and kitchen-related fires, including grease and cooking oil Fire extinguishing agents (i.e., potassium citrate, potassium acetate, or potassium carbonate) cover flammable liquids to starve them of oxygen

Determining the Placement of Fire Extinguishers

Determining the ideal location of boat fire extinguishers is crucial to ensure optimum fire safety.

1. US Coast Guard requirements


A US Coast Guard requirement is to place the correct fire extinguisher type and number in the following places on a boat.

  • Closed compartments for storing portable fuel containers or tanks
  • Closed living quarters or spaces
  • Double bottoms without sufficient floatation material or unsealed to the vessel’s hull
  • Fixed fuel tanks
  • Closed compartments for storing flammable or combustible items and materials

2. Different fire hazard areas


Onboard fires can start anywhere on a boat. However, fires often start in the following sections.

  • Boiler rooms
  • Engine rooms
  • Rooms with heavy machinery
  • Compartments with combustible and flammable materials

3. Specific guidelines for placement and accessibility


Here are some guidelines every boat operator and crew must know about fire extinguisher placement.

  • Class A fire extinguishers must be accessible within 75 feet.
  • Class B fire extinguishers must be accessible within 30 to 50 feet, depending on the nature of the fire.
  • Fire extinguishers weighing less than 40 pounds must be mounted in wall cabinets or brackets with the carrying handle not exceeding a height of five feet from the floor surface.

Additional Considerations


Determining the number of fire extinguishers to comply with marine fire safety standards requires considering the following factors.

  • Boat size – The longer and heavier (higher gross tonnage) your boat is, the more fire extinguishers you will need.
  • Boat type – Not all vessels require a fire extinguisher. For example, watercraft with outboard engines in an open design doesn’t need fire extinguishers.
  • Devices – A built-in fire suppression system in the engine compartment reduces the number of B-5 extinguishers by one. Moreover, the types of flammable and combustible materials will dictate how many Class A, Class B, and Class C fire extinguishers you need. Hence, most boaters use Class ABC units.

Installing and Maintaining Boat Fire Extinguishers


Boaters should store fire extinguishers in a vessel section readily visible and accessible to anyone. Maintaining fire extinguishers include the following activities.

  • Check the fire extinguisher gauge to ensure it’s charged.
  • Assess the pin lock, ensuring it’s in its rightful place,
  • Check the tank for signs of damage, corrosion, and other signs of loss of integrity.
  • Ensure the discharge nozzle is free of obstacles.

Fire Safety Best Practices on Boats


Here are the best practices for ensuring fire safety on boats.

  • Use only Coast Guard-approved fire extinguisher systems.
  • Install smoke alarms, gas leak indicators, and carbon monoxide alarms.
  • Turn off all electric and heat-related appliances and devices properly after use.
  • Avoid smoking or lighting candles if drowsy.
  • Observe routine boa engine maintenance checks.
  • Learn fuel and gas safety protocols on boats.
  • Prepare a safe evacuation plan in case of onboard fires.

Frequently Asked Questions


Which class of fire extinguishers should be onboard a vessel with a permanently installed fuel tank?

Fuel is a flammable liquid. Hence, you need a Class B fire extinguisher, although Class ABC and Class BC also work.

Can I use a household fire extinguisher on my boat?

No, you must only use USCG-approved fire extinguishers in putting out fires on boats. Check if the unit also has a UL seal.

How often should I inspect and maintain my boat’s fire extinguishers?

Fire extinguishers with dry chemicals require inspection and testing every dozen years. For all other types, the frequency is every five years.

Do boat fire extinguishers expire?

Yes, boat fire extinguishers expire. Regardless of the brand (i.e., West Marine fire extinguisher), boaters must replace their extinguishers every 12 years.


Remembering the boat fire extinguisher requirements is easy. You need at least one 5-B type for vessels under 26 feet, while boats between 26 and 40 feet need one 20-B or a pair of 5-B extinguishers. Larger vessels up to 65 feet long need three 5-B or one of the 5-B and 20-B devices.

Please note these USCG requirements because you’ll never know when fires break out on board. Hence, knowing where to place these safety devices and how to maintain them is equally important.

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