A fire on board is one of the biggest potential dangers we face at sea and can ravage a vessel in minutes. Fire prevention is critical (see: Onboard fire prevention: 7 safety essentials) but any fire that does start is an emergency situation that requires the correct action to be taken immediately and demands that you have the correct armoury of tools ready for instant action.

In particular, don’t be tempted to economise with small extinguishers – you need to be confident they are up to the job and have sufficient capacity, with plenty in reserve in case the blaze flares up a second time before the source of the fire fully cools down to ambient temperatures. On my own 30ft and 36ft boats I carry a 2kg extinguisher near each exit from the accommodation, although significantly larger vessels will need additional capacity.

Fire extinguisher

Extinguishers should be serviced annually and dry powder types replaced after five years.

Early action is essential

It’s impossible to over emphasise this point – much depends on what happens in the first 60-120 seconds after a fire breaks out. Flames can spread alarmingly quickly over the combustible surfaces of the interior of a yacht, so never worry about creating unnecessary mess by firing off a dry powder extinguisher at a small fire that might at initially look as though it could be easily put out by other means.

As with other on-board emergency situations, it’s important to approach the problem with a clear head and not to allow panic to set in. Dry powder extinguishers need to be pointed at the base of the flames – ie. at the root source of the fire, otherwise you are in effect spraying the powder in mid-air. Even after a blaze appears to have been extinguished it’s crucial to monitor the situation for a long time afterwards – potentially several hours – to ensure that residual heat does not cause it to flare up again. It’s important not to discount the possibility of this happening, as woodwork, for instance, may still be warm enough to continue slowly smouldering for a considerable length of time.

Fortunately fire extinguishers are impressively effective, especially on fires that have not had time to take a firm hold. Usually within a couple of minutes you will know whether the fire is under control, or whether you need to prepare to abandon ship.

In any case, immediately on discovering a fire any off-watch crew should be woken, a Mayday sent and the EPIRB activated. Make preparations for abandoning ship as soon as it’s clear that the fire cannot be contained this is the one case where boarding the liferaft early makes sense – and you need to get clear of the yacht before either flames or heat reach the fuel tank and gas bottles.

Engine fires

Do not remove the engine cover if there’s a fire in the engine compartment as doing so will fuel the fire by allowing more oxygen to reach it. There should be an aperture in the compartment (usually near the companionway steps) which the nozzle of a fire extinguisher can be poked through. However, it’s much better to install the automatic type of extinguisher that is self-activating in the event of an engine compartment fire.

Engine compartment

Automatic extinguishers in engine compartments need to be interfaced with the ventilation system so that all vents close automatically in the event of an engine fire.

In the event of a galley fire, turn the gas off at the bottle and place the fire blanket over the flames, protecting your hands by wrapping the corners of the blanket around them.

Specifying fire fighting equipment

Unfortunately, most yachts have not been the subject of a comprehensive survey to analyse their fire fighting requirements and many are woefully under-equipped as a result. The larger and more complex the vessel, the more important this aspect becomes.

For a start, each extinguisher must of a suitable size for the volume of the space in which it is intended to be used. This is particularly true for engine compartment extinguishers, where if there’s too little extinguishant an engine fire could easily restart. An additional common problem affecting boats with larger motors is engine room ventilation systems that do not automatically switch off when the extinguisher is activated. This arrangement will simply remove the extinguishing medium and replace it with new oxygen-laden air – the worst possible scenario.

If you’re worried that your system may not be up to scratch the best solution is to engage a specialist marine fire contractor to inspect your boat, measure the volume of the various parts of the interior and specify a suitable system.

Maintenance of fire-fighting systems

It’s all too easy to overlook fire fighting appliances when undertaking annual maintenance. All types of fire extinguisher should be checked each year at a specialist service centre. The procedure they undertake includes checking the operation of the gauge, weighing the cylinder to confirm the quantity of extinguishant remaining, plus inspecting for other problems such as corrosion.

Even with annual servicing, dry powder and foam extinguishers have a service life of just five years, although gas types last twice as long. Fire blankets should also be checked annually, as the modern fibreglass types (as distinct from older asbestos versions that should in any case be replaced) may eventually develop holes at the creases where they are folded.

For more on fire prevention and safety afloat, see: Fire at sea: crew rescued from burning boat and 14 tips to make sure your safety gear is in order. Winter fires on board are also easily preventable: How to choose and install boat heating and 5 ways to protect your boat over winter.

Written by: Rupert Holmes
Rupert Holmes has more than 70,000 miles of offshore cruising and racing experience, in waters ranging from the North Sea to the Southern Ocean and Cape Horn. He writes about all aspects of boat ownership and marine travel, including destinations, seamanship and maintenance, as well as undertaking regular new boat and gear tests. He currently sails around 5,000 miles per year and in the past couple of seasons has cruised from the UK to the Azores, as well as winning his class in the 2014 two-handed Round Britain and Ireland Race. He also owns two yachts, one based in the Mediterranean and the other in the UK.