A fire on a boat is the emergency that frightens me most, more than a knockdown or a grounding. You cannot step off into a corridor. The fuel, the gas and the lithium are all aboard with you, the GRP hull and the soft furnishings burn well, and the clock is brutal. Fire experts reckon a new fire can double in size every 30 to 60 seconds, and that if you have not got on top of it within about two minutes you are too late to fight it. So the whole game is won before there is any flame: in how the boat is wired, how the galley is run, and whether the crew know where the extinguishers are without looking.
Where boat fires actually start
The data is unambiguous about the biggest culprit. Electrical faults, in both DC and AC systems, account for roughly 55 per cent of onboard fire insurance claims. That is more than every other cause put together. On the AC side, the classic ignition point is the shore power connection: most AC fires start somewhere between the marina pedestal and the boat's shore power inlet, where corroded or loose connections heat up under load. In a busy French marina you plug into a different pedestal every few nights, and a tired socket on the dock can cook your inlet overnight.
After electrics, the galley is the next big one. Cooking accidents and unattended stoves are a regular cause, and a galley fire spreads fast because it sits among curtains, cushions and a gas supply. On older outboards, the voltage regulator is the single most common fire source, with failure rates climbing once the engine passes ten years old.
That tells you where to put your attention. Inspect the shore power inlet and lead for browning or melting. Do not run high loads through a doubtful connection. Never leave a hob lit and walk away, however briefly. And keep an eye on ageing electrical kit.
Building fire out of the boat
Prevention on a visiting boat comes down to a short, boring routine.
- Check the shore lead and inlet every time you plug in. If the inlet is warm to the touch under load, stop using it and get it looked at.
- Turn the gas off at the bottle, not just the hob, whenever you finish cooking. A solenoid switch at the chart table makes this a habit rather than a chore.
- Keep a fire blanket within arm's reach of the cooker, mounted where you can grab it without reaching across flames.
- Do not stow petrol, gas bottles or charging lithium in a sealed, unventilated locker.
- Fit a smoke alarm in the saloon and one near the engine space, and test them at the start of the season.
Gas deserves its own discipline because the French equipment rules expect a properly installed and maintained system, and because a gas leak in the bilge is a floating bomb. If you want the detail on bottle types and connections, the differences between Calor and French gas bottles trip up a lot of British boats arriving for the season.
The right extinguishers, in the right places
For a yacht the practical answer is multipurpose dry powder. The American Boat and Yacht Council recommends ABC extinguishers for most boats under about 65 feet because they cover the three fire classes you might face: Class A, the solids like wood, cloth and the GRP of the hull itself; Class B, flammable liquids like petrol and diesel; and Class C, electrical fires. One type that handles all three removes the fatal hesitation of working out which bottle to grab while the curtains go up.
Where you put them matters as much as how many you carry. You want one by the companionway so you are never trapped below by a fire between you and the deck, one near the galley but not directly above the cooker, and one accessible to the cockpit. The engine space wants its own protection, ideally a fixed automatic extinguisher or at minimum a fire port so you can discharge into the compartment without opening the lid and feeding the fire a lungful of oxygen. Opening an engine box onto a fire is exactly the wrong move.
Check the gauges at the start of every season and after any rough passage, and have powder extinguishers shaken or serviced so the contents have not caked.
Fighting it, if it comes to that
If a fire starts, the order of priorities is fixed: get the crew safe first, then fight the fire only if you can do so without putting anyone at risk. With an engine fire, kill the engine and the fuel supply and use the fire port; do not lift the lid. With a galley fire, cut the gas at the bottle and smother with the blanket. Aim an extinguisher at the base of the flames, not the top, in short bursts.
Through all of this someone should be on the radio. The two-minute window means you call for help early, not after you have lost the fight. A fire is a grave and imminent danger, which makes it a mayday, and you should put it out on channel 16 the moment the fire looks like it might win, while you still have power and a radio. Have the French distress and safety call procedure written on a card by the set, because nobody composes a calm mayday with smoke in the cabin. CROSS will coordinate the response, and knowing which French CROSS coastguard station covers your water means you understand who is answering.
The crew brief that takes five minutes
The single cheapest improvement you can make to fire safety costs nothing and takes about five minutes at the start of a cruise. Walk the crew round the boat and show them, physically, where every extinguisher lives, how the pin pulls and how the trigger works. Show them where the fire blanket is and how it comes out of its pouch. Point out the gas bottle and how you turn it off. Show them the engine fire port if you have one, and explain why you never open the engine box onto a fire.
Then agree roles for the first thirty seconds, because that is the window that decides everything. Who grabs the nearest extinguisher. Who kills the gas and the engine. Who gets on the radio. Who counts heads and gets lifejackets out. On a short-handed boat one person may wear two of those hats, but having decided in advance beats improvising with smoke in the cabin. Crews who have never discussed it freeze, look at each other, and lose the two minutes that mattered.
I also brief guests who have never sailed before on exactly two things: where the extinguisher by the companionway is, and that if I shout fire they put their lifejacket on and come on deck. That is enough. Detail overwhelms people in an emergency; a single clear instruction does not.
Detecting it before you smell it
A fire you catch in its first seconds is a fire you put out. A fire you discover when the cabin is already full of smoke is one you may only survive. That gap is what smoke and gas detection buys you. A simple smoke alarm in the saloon and another near the engine space will wake you to a smouldering fault long before it flames, and they cost almost nothing. A gas alarm with a sensor low in the bilge catches a leak before it finds an ignition source. Test them when you commission the boat and carry spare batteries, because a chirping alarm that gets unplugged to stop the noise is worse than no alarm at all.
When the boat is lost
There is a point where fighting stops and survival begins. If the fire is beating you, if it has reached the fuel or the gas, or if the cabin is filling with smoke faster than you can clear it, you abandon. That is a decision made early, not at the last gasp, because a fire that has the upper hand moves faster than you can launch a liferaft. Lifejackets on, mayday sent or DSC alert triggered, grab bag and EPIRB out, and off into the raft. The mechanics of doing that calmly are worth rehearsing on a quiet day, and I have set them out in abandoning to the liferaft.
The boats that burn to the waterline are rarely the ones with a clever extinguisher. They are the ones where a tired shore lead was left plugged in, or a hob was left lit, or nobody had agreed who does what in the first thirty seconds. Win it at the dock, and you will probably never have to fight it at sea.
