Requirements For Fire Extinguishers On A Boat

Many boat owners struggle with understanding the specific requirements for fire extinguishers on their vessels.

Drawing from an extensive understanding of US Coast Guard regulations, as well as practical insights, this article provides a thorough guide to fire extinguisher requirements on boats.

Whether you’re a seasoned sailor or a recreational boater, I’ll use clear, straightforward language to explain complex regulations, making your life easier.

As a fellow boating enthusiast, I understand the importance of safety on the water. Let’s take a quick look at the main takeaways:

At a Glance:

1️⃣ The US Coast Guard requires fire extinguishers to be carried in boats that are 26 feet or longer or have other defined facilities (described below).

2️⃣ Different categories of boats require different types of fire extinguishers.

3️⃣ It is important to install the most appropriate type of fire extinguishers depending on the varying risks found around a boat.

What Recreational Boats Require Fire Extinguishers?

The vessels required to carry Marine Type – USCG Approved fire extinguishers are as follows:

  • A fire extinguisher must be installed if the boat is longer than 26 feet.
  • If the boat has an enclosed living area, fire extinguishers must be installed.
  • All recreational boats with an installed gas tank must carry fire extinguishers.
  • If the boat has inboard engines or sterndrives installed in an enclosed compartment, fire extinguishers must be installed.
  • If the boat has a double bottom that is not filled with flotation material and may be able to trap fumes, it must have a fire extinguisher.
  • The boat must have a fire extinguisher if combustible or flammable materials are stowed in an enclosed area.
  • B-class or A-class dry chemical portable fire extinguishers are recommended to deal with electrical and combustible fires.

If the boat is under 26 feet long and uses an outboard motor with a portable gas tank, it does NOT require a fire extinguisher.

While the law may not prescribe that fire extinguishers be carried, it is not advisable, and in our opinion, even if it is not a legislated requirement, all boats must have a fire extinguisher installed.

Marine fire extinguisher requirements do not specify where fire extinguishers should be mounted.

In addition to the regulations, you should also understand who is responsible for explaining fire safety procedures to passengers.

🔢 How Many, And What Size Fire Extinguishers Must Be Carried

The number of fire extinguishers that are required is shown below.

Length Of BoatThe minimum number of “5-B” units that are required
If there is no installed fire suppression system in the engine roomIf there is an installed fire suppression system in the engine room
Under 16 feet1️⃣0️⃣
Greater than 16 feet and less than 26 feet1️⃣0️⃣
Greater than 26 feet and less than 40 feet2️⃣1️⃣
Greater than 40 feet and less than 65 feet3️⃣2️⃣

The regulations allow a different combination of fire extinguishers to be carried on board, dependent on when the boat was manufactured.

Boats Manufactured After 2017

For boats manufactured in 2018 and later, the installation of 5-B and 20-B fire extinguishers is mandatory.

It is permissible to have a single 20-B fire extinguisher instead of two 5-B extinguishers. Class B fires are prevalent on boats, which is why the US Coast Guard mandates class B marine fire extinguishers.

Boats Manufactured Between 1953 And 2017

Boats manufactured between 1953 and 2017 are allowed to carry the following fire extinguishers:

Unexpired 5-B or 20-B rated fire extinguishers.


B-I or B-II-rated fire extinguishers that are in good and serviceable condition.

One 20-B or B-II fire extinguisher can be used instead of two 5-B or two B-I fire extinguishers. 

In both instances, a single “10-B” extinguisher cannot replace two “5-B” extinguishers.

🧯 What Type Of Fire Extinguishers Must Be Mounted In A Boat?

The appropriate fire extinguishers should be mounted in a boat. 

On a larger boat, there are four locations that generally have different fire hazards:

  • The galley.
  • The engine room /compartment.
  • The general living areas.
  • electrical compartments

The following lists the fire extinguishers suitable for fighting fires fueled by different fuels and ignition sources:

On larger boats that have areas that are used for different functions (and therefore present different fire risks), such as galley/dining area, engine bay, wheelhouse, and sleeping cabins.

The most appropriate category of fire extinguishers should be located in an easy-to-reach position for every location.

The type of fire extinguisher installed in or near any risk location must be selected correctly to ensure that it uses the most effective firefighting chemistry against differently fueled fires.  

The following list summarizes the most appropriate fire extinguisher types that can be used to fight differently fueled fires.

Class Of FireType of fuelAppropriate Fire extinguisher to use 
WaterFoamDry PowderCarbon Dioxide CO2Wet ChemicalClean agent
Class AIncludes Materials Like Wood, Paper, Textile, Rubber, And Cloth✔️✔️✔️✔️
Combustible Materials
Class B Including Petrol, Diesel, Oils, Greases, Solvents, Alcohols, And Oil-Based Paints. ✔️✔️✔️
Flammable liquids
Class C Include Gasses Such As Hydrogen, LPG, And Butane✔️✔️
Flammable gases
Class DIncluding Aluminum, Titanium, Magnesium, Lithium, Zirconium, Sodium, And Potassium✔️
Combustible Metals
Class EElectrical Contact✔️✔️✔️
Electrical Fires
Class F Examples Are Cooking Oil Or Fats That Require Temperatures Over 340°C To Ignite.✔️
Flammable liquids or gases differ from Class B and Class C fires due to the extremely high temperatures involved.

🚤 Fire Extinguisher Selection By Type Of Boat

Using the wrong fire extinguisher against different types of fires is counterintuitive and may cause the fire to increase in intensity and spread.

The following section identifies the most appropriate fire extinguishers to be carried out on the different categories of boats. 

Sailboats are not necessarily exempt. The rule mainly applies to motorboats with permanently installed fuel tanks or a storage area where portable fuel tanks may be stored.

However, the rule also applies to sailboats with spaces that are capable of trapping fumes, such as a galley, and to sailboats with auxiliary engines.

Smaller Gas-Powered Recreational Boats (Bowriders, Wake Boats, etc.)

In small boats, the main fire risk stems from the gas tanks and fuel lines (Class B or C fires).

If the boat has an enclosed inboard or sterndrive motor, it is required to carry fire extinguishers.

The most effective fire extinguishers in an engine compartment fire are:

  • Foam
  • Dry Powder
  • Carbon Dioxide CO2

Don’t install the fire extinguisher inside the engine compartment where access may be difficult (or it is too hot).

Always install these fire extinguishers immediately outside the hatch to the engine compartment.

So, learn about the best practices for storing fire extinguishers on a boat before you start mounting any in the wrong place.

Larger Live Aboard Vessel

A bigger vessel may have several different fire risks associated with it. These may include the following:

  • A Fire in the engine compartment (Classes A and B)
  • A galley Fire (Classes A or F)
  • A fire in the electrical compartment, even if it is under a bunk (Class E)

A Fire In The Engine Compartment (Classes A and B)

Engine compartments on larger vessels are fire-prone due to limited space and maneuverability.

Despite diesel engines being lower risk, firefighting in these areas remains challenging. Prioritize fire safety preparations to mitigate potential hazards.

Always exercise appropriate precautions (as listed below) when using the engine room.

The engine room is not a storage room. Always remove old cans of gas, grease paint, oil-covered rags, and other flammable liquids.

Keep the engine room clean –a leaking fuel pipe or another fire hazard can be quickly identified and dealt with.

The most effective fire extinguishers in an engine compartment fire are listed below.

  • Foam
  • Dry Powder
  • Carbon Dioxide CO2

Once again, don’t install the fire extinguisher inside the engine compartment where access may be difficult (or too hot). Always install these fire extinguishers immediately outside the hatch to the engine compartment.

A Fire In The Galley (Classes A or F)

The galley potentially contains all the possible fuels that can be used to ignite and maintain a fire. In addition, a fire that starts from one fuel may spread to include other fuels.

This makes selecting the most appropriate fire extinguisher for the galley important.

The fire extinguishers most effective with galley fires (and the different fuel sources) are listed below.

  • Dry Powder (Classes A, B, and C fires)
  • Carbon Dioxide CO2. (Classes B, C, and E fires)
  • Wet Chemical (Classes E and F fires).

Fire Extinguishers In The Electrical Room

If the vessel has a separate electrical compartment, it may contain the following equipment:

Batteries; Inverter(s) – solar power; DB Board; Cabling; Navigation computer; Autopilot computer; Master fuses for the lighting system.

Although the chance of a fire starting is low (a lightning strike is more likely), an appropriate fire extinguisher should be installed.

Possible causes of an electrically ignited fire include:

  • Appliances that use more amperage than the wiring is designed for.
  • Old wiring looms.
  • Faulty voltage regulators.
  • Incorrect (or too loose) installation of battery cables.

The most effective fire extinguishers in an engine compartment fire are listed below.

  • Carbon Dioxide CO2
  • Wet Chemical

Fire Extinguishers For The General Areas

A dry powder or foam fire extinguisher should always be kept to fight fires on the deck, living areas, and bridge deck. 

🔑 Key Takeaways

In most instances, carrying fire extinguishers on a boat is a legal requirement. 

1️⃣ Even if some boats are not leaglly required to carry a fire extinguisher, it is good practice to do so.

2️⃣ The type of fire extinguishers that are installed should relate to the type of fire risk that is present.

3️⃣ The mounting position must be carefully chosen and always needs to be accessible in case of fire.

Unless it is quickly attended to and extinguished, a boat fire is frightening and can quickly get out of control.

Carrying the correct fire extinguishers that are easy to access offers the only chance to get it under control.

Next, I’d suggest reviewing our boat inspection checklist to ensure all fire extinguisher requirements are met.

❓ FAQs

How often should I inspect and maintain the fire extinguishers on my boat?

Fire extinguishers should be inspected regularly to ensure they are in good working condition. This includes checking for any visible signs of damage, the pressure gauge, and making sure the pull pin is intact. It’s recommended to have your fire extinguishers professionally inspected at least once a year.

What should I do if my boat’s fire extinguisher is expired or damaged?

If your boat’s fire extinguisher is expired or damaged, it’s crucial to replace it immediately. An expired or damaged fire extinguisher may not function properly in the event of a fire.

I’m the founder and chief editor here at Sailing Savvy. I spent a decade working as a professional mariner and currently, I mix those experiences with digital publishing. Welcome, and I hope that we can be the hub you need for safe passage.