What Is The Best Fire Extinguisher For A Boat?

The best fire extinguisher for a boat is typically a marine-rated fire extinguisher, for example, by the US Coast Guard approved. In addition, the best type of extinguisher depends on what class of fires you could potentially expect to deal with on board.

A boat fire is every mariner’s nightmare. The combination of different sources of fuels that feed a fire, flammable materials, and insufficient space to keep people safe results in the perfect storm of fire risks.

At a Glance:

1️⃣ The US Coast Guard (USCG) has strict regulations in terms of fire extinguisher requirements.

2️⃣ Fire extinguishers should be regularly inspected.

3️⃣ The most appropriate type of fire extinguisher must be installed at each location.

4️⃣ A plan describing the steps needed to follow if a fire starts essentially.

🧯 Marine Fire Extinguisher Requirements

The USCG requires fire extinguishers to be carried in different categories of vessels.

Irrespective of a boat’s length, the following features in the vessel also require fire extinguishers:

  • Vessels with an enclosed living area are required to carry fire extinguishers.
  • Any recreational boat with a permanently installed gas tank must carry fire extinguishers.
  • Vessels with inboard engines or stern drives enclosed in an engine compartment require fire extinguishers.
  • A boat with a flotation space in the hull that is not filled with a flotation material and, therefore, may trap fuel spills must have a fire extinguisher.
  • If combustible or flammable materials are stowed in an enclosed compartment or cabin, they must have an extinguisher.

Ensuring that your fire fighting equipment meets regulations isn’t just checking a box. It’s ultimately for your own safety.

Size And Capacity

Irrespective of these requirements, fire extinguishers must be carried in boats of the following lengths:

Boat LengthFire Extinguisher Requirement
Less than 26 feetSingle 5-B fire extinguisher
Between 26 and 40 feetTwo 5-B fire extinguishers or one 20-B fire extinguisher
Between 40 and 65 feetThree 5-B fire extinguishers or a single 20-B and a 5-B fire extinguisher

The following exceptions apply.

Boats Manufactured Between 1953-2017 And after 2017

Boat Manufacture DateFire Extinguisher RequirementSubstitutions
Between 1953 and 20175-B rated fire extinguisherOne 20-B fire extinguisher may substitute two 5-B extinguishers
20-B rated fire extinguisherOne 20-B fire extinguisher may substitute two 5-B extinguishers
B-I fire extinguisherOne B-II may substitute two B-I extinguishers
B-II fire extinguisherOne B-II may substitute two B-I extinguishers
A 10-B fire extinguisher may not substitute two “5-B” extinguishers
After 20175-B and 20-B fire extinguishersA single 20-B fire extinguisher can substitute two 5-B fire extinguishers


Once you’ve got an idea of which fire extinguishers you need, learn about where fire extinguishers should be stored on a boat.

These locations are summarized in the list below.

PositionType Of Fire ExtinguisherCategory Fire RiskType of Combustion Material
The Engine CompartmentFoam, Dry Powder, or Carbon Dioxide CO2Class BPetrol, Diesel, Oils, Greases, Solvents, Alcohols, And Oil-Based Paints.
If the boat has installed Gas TanksFoam, Dry Powder, or Carbon Dioxide CO2Class BPetrol, Diesel, Oils, Greases,
Living AreasWater, Foam, Dry Powder, Wet ChemicalClass AWood, Paper, Textile, Rubber, And Cloth
GalleysWet ChemicalClass FCooking Oil Or Fats
Electrical CompartmentsCarbon Dioxide CO2, Wet Chemical, Clean agentClass EBattery installations, Inverters, Autopilot equipment, radios.
Toxic Or Flammable MaterialsDry Powder, Carbon Dioxide CO2Class CInclude portable gas tanks Such As Hydrogen, LPG, And Butane

Labeling And Inspection

The extinguishers must be inspected and labeled in terms of regulations.

Annual Inspection

Fire extinguishers should be inspected annually with the following information being completed on the label:

  • The inspector’s (and company) name.
  • The last inspection date (month and year.)
  • The inspector’s license or certification number.
  • Type Of Fire Extinguisher chemical that is contained in the canister.
  • A hole is punched under the inspection tag.
  • The status tag located at the bottom of the canister musts displays “Serviced, New, or, Recharged.”

Six Year Inspection

Every six years, the fire extinguishers require a more thorough check where they are carefully examined by a licensed technician.

This inspection includes the following process:

  • The extinguisher is emptied.
  • The mechanical components are checked and, if necessary, replaced.
  • The condition of the outlet hose and delivery system are checked and repaired if necessary.
  • The canister is refilled.
  • The documentation and labels are updated.

🎯 Choosing The Best Fire Extinguisher For Your Boat

The selection of fire extinguishers is governed by USCG regulation requirements and the fire risk that is present on the vessel.

Boat Size And Type

The regulations dictate the minimum number of fire extinguishers required in different-sized boats.

Although discussed earlier, the requirements are summarized in the list below.

Length Of BoatThe number “5-B” fire extinguishers required as a minimum
Boats with no fire suppression system in the engine compartmentBoats with a working fire suppression system in the engine compartment
Vessels less than 16 feet10
Vessels between 16 and 26 feet10
Vessels between 26 and 40 feet21
Vessels between 40 and 65 feet32

Fire Types

The table in this article details the type of fire extinguishers that should be installed for the different fire risks on the boat. 

There are four different classes of fire. Class A fires, Class B fires, Class C fires, and Class D fires.

🅰️ Class A fires are those that burn combustibles like wood and paper.

Water is best to fight with Class A fire only. 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 fire extinguishers put out fires of liquids such as oil, paint thinners, and gasoline. Class B fire extinguishers have carbon dioxide, dry chemicals, or AFFF (Aqueous Film-Forming Foam).

©️ Class C fire extinguishers are used in fires caused by electric charge or equipment.

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.

The extinguishing agents are usually sodium bicarbonate or potassium bicarbonate for Class B and C fires.

Extinguishers that are also rated for Class A fires usually contain mono-ammonium phosphate.

This is a highly corrosive chemical, so if you use an ABC unit to put out a live electrical fire in the nav station, you’re likely to damage your electronics.

Ease Of Use

In a fire emergency, the correct time-critical response may be the difference between survival and disaster.

The last thing you need is to struggle with is trying to work the fire extinguisher.

Maintenance And Expiration

Regulations require that the fire extinguishers are maintained in good and serviceable condition. This means:

  • The fire extinguisher must be full, and if it has a pressure gauge, this must reflect this.
  • All safety pins and/or locks must be in position.
  • The external appearance of the canister and nozzle must show no signs of corrosion or damage.
  • The nozzle must be clean and clear of any obstructions or blockages.

The fire extinguishers must also not be expired, and the annual and six-yearly inspections must be complied with.

🦺 Safety Tips For Boating Fire Prevention And Response

A fire emergency on a boat must be handled immediately and appropriately. This means that the most suitable type of fire extinguisher must be used for each type of fire.

Spraying water on a fuel-fed fire will only spread the fire while using a CO2 extinguisher in a living area increases the risk of injury.

Proper Installation

All fire extinguishers must be securely installed near high-risk areas where they can be accessed immediately.

Find out how to mount fire extinguishers so that you can easily use them.

Irrespective of the regulations, a suitable fire extinguisher must be installed if the vessel has the following facilities:

  • A galley that has a gas cooker and stores of cooking fat or oils.
  • The engine compartment.
  • Close to the gas tanks.
  • Close to any compartments that have stored fuel.
  • Within easy reach of the cockpit.

Routine Maintenance

All fire extinguishers should be checked monthly by the owner.

The annual and six-yearly checks must be performed by a registered technician.

Emergency Action Plan

Fires in boats quickly spread and need to be fought immediately. Instead of waiting for a fire event, it is good practice to have thought out and practiced the action you will take for each fire type.

This includes the provision of a ditch bag that has all of the equipment that is needed if the boat is abandoned.

Key Takeaways

A fire emergency on a boat is a serious event and, if not handled immediately, will result in the loss of the vessel and possible injury to the occupants.

It’s important to know who is responsible for explaining fire safety procedures to passengers to avoid potential casualties.

Let’s summarize what to take into account to determine the best fire extinguihers for your boat.

1️⃣ Always be aware of the fire risks.

2️⃣ Install more than the minimum number of fire exit extinguishers on a boat.

3️⃣ Ensure that they are serviced.

4️⃣ Have a plan in place on how to fight fires and what each person’s duty is.

Safety at sea is never a subject that should be taken lightly, and we recommend that you research it as much as possible.

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.