Boat Fire Extinguisher Requirements | BSS Rules by Boat Length

Portable fire extinguishers are one of the ten most common reasons boats fail a Boat Safety Scheme (BSS) examination. This guide sets out what the BSS checks, using the BSS’s own checking procedures for privately owned boats.

How many extinguishers do you need?

The BSS sets a minimum number of extinguishers and a minimum combined fire rating, based on the length of your boat.

Length of boat	Minimum number	Minimum combined fire rating
Under 7m (23ft)	2	10A/68B
7m to 11m (23ft to 36ft)	2	13A/89B
Over 11m (36ft)	3	21A/144B

To count towards this, each extinguisher must:

have its own fire rating of at least 5A/34B
carry at least one accredited third-party certification mark
be in good condition (see below)

If your boat has no internal combustion engine, or no fuel-burning appliances, the minimum can be reduced by one 5A/34B extinguisher.

Fuel-burning appliances include those using LPG, diesel, paraffin, spirit and solid fuel.

What the fire rating means

A rating such as 5A/34B shows the class of fire (A for solids, B for liquids) and the size of test fire the extinguisher put out. Bigger numbers mean a bigger test fire.

5A/34B is the smallest the BSS accepts. The BSS points out that a 5A/34B dry powder extinguisher is likely to last only around ten seconds. It is for knocking down a small fire, or knocking it back so people can escape.

What “good condition” means

The examiner will fail an extinguisher that shows any of these:

missing safety pin
dents, gouges, or significant rust or corrosion
a perished hose
a pressure gauge in the red
damage to the trigger, including damage from sunlight or heat

An extinguisher past the manufacturer’s warranty date is not, on its own, a sign of poor condition.

Servicing

The BSS does not require extinguishers to be serviced. If BS 5306 is printed on your extinguisher, the BSS recommends having it serviced to that standard. Some extinguishers are “service-free”. For those, inspect them as the manufacturer says. If you are not sure which type you have, ask the manufacturer.

Where to put them

Spread them around the boat, next to escape routes.
Make sure they are easy to reach.
Do not place one where you would have to reach over the cooker to get it.
Keep them in open view, or put a clear label in open view showing where they are.

Fixed brackets are not a BSS requirement, but the BSS strongly recommends them.

Fire blankets

If your boat has permanently installed cooking facilities, you need a fire blanket. A microwave does not count.

It must be marked BS EN 1869 or BS 6575.
It must be within about 2m of the main cooking appliance, usually the hob.
You must not have to reach over the cooker to get it.

Fixing the blanket’s container permanently in place is not a requirement for private boats, but the BSS strongly recommends it.

Replace a fire blanket after you have used it. Even a small flaw can make it useless.

More than the minimum

You can carry more extinguishers than the minimum. The BSS requirements are minimums. Any extra extinguishers that have no certification mark, or are in poor condition, should be removed or replaced.

The BSS does not set rules for fixed systems in engine spaces. It does encourage owners to consider an automatic system in the engine space, fitted by a competent installer.

If a fire starts

The BSS Fire Safety on Boats leaflet advises:

Only use an extinguisher on a small fire, or to help you escape past flames.
If in doubt, get out, stay out and call 999.
Learn how to use the extinguishers on board before you need them.
Expect a dry powder extinguisher to create a dense cloud that makes it hard to see and breathe.

Before your examination

Count your extinguishers and add up their ratings against the table above.
Look for the certification mark on each one.
Check each for a pin, damage, corrosion and the gauge reading.
Check they are near escape routes and in view, or labelled.
Check your fire blanket’s marking and position.

Sources

All read 20 Oct 2026.