An onboard fire can start in all kinds of ways, from a dish towel falling on a hot stove while you’re cooking, or from the back of a corroded shore power inlet while you’re asleep. Safety and alarm systems can warn you that there’s a fire, and hopefully put it out—but the more time you spend on prevention, the less likely it is that you’ll actually have to fight a fire.

Here’s a look at smart prevention tips, as well as how to be prepared in case a fire gains the upper hand on your boat.

The Basics

A major factor in prevention is how well the operational systems are installed on a boat, and how well they are maintained. Prevention also includes general housekeeping: Keeping combustible items away from open flames or hot equipment is low-hanging fruit. So is keeping a boat tidy. If access is needed quickly, gear needs to be shifted first, giving flames time to spread.

Also key: Make sure all the wiring on the boat is installed to American Boat and Yacht Council standards. Many boat fires start in the wiring, either from lack of proper overcurrent protection (fuses and breakers) or from high-resistance connections, which won’t always trip a breaker or blow a fuse, but can generate enough heat to melt wiring and start a fire.

High-resistance connections can occur in just about any circuit, but they are especially prevalent in shore-power inlets, battery and battery-switch cabling, bow and stern thrusters, windlass connections in wet locations, and alternator and battery-charger wiring. The more amperage a device uses, the more risk there is. Vibration on a boat can easily shake loose secured wiring. The ABYC recommends securely tying wires and cables every 16 inches along a wire run; having explicit instructions to prevent wire chafe; covering high-amperage and AC connections against accidental exposure; and frequently checking the torque of connections.

As battery banks become larger and battery chemistries are engineered to produce quicker output and denser power, attention needs to be given to amperage interrupting capacity. The fuses and breakers that worked for a boat’s original wet-cell batteries may not be rated for a larger, more powerful bank. Failure to upgrade the circuit protection can result in the circuit protection melting closed in the event of a short circuit, potentially causing the wiring to heat to the point of fire.

In the Galley

The act of heating food aboard is fraught with danger. Whether it’s the explosion risk with alcohol or propane stoves, or an open flame or an electric cooktop’s red-hot burner, the area around the stove needs to be free of combustibles. Heat shields, hoods and counter space should be part of the design, along with carefully placed fire blankets, fire extinguishers and propane solenoid shut-off switches, all within easy reach (but not over the stove, where a flame would prevent you from reaching it).

If the boat has enough AC generation, then induction cooktops are an option. They cook food quickly and are significantly safer, with no open flame or resistance burner.

A fire blanket can also be an effective first response to a galley fire. Smothering a fire is considerably less messy than cleaning up after using a fire extinguisher—which of course should be used if necessary.

In Engine Rooms

Failures in the cooling system can cause not only the engine, but also the exhaust system to overheat. Exhaust over-temperature alarms can quickly alert you to this problem and are an ABYC requirement for new boats.

For wet exhaust systems, the dry section of pipe prior to the water injection elbow should be insulated with lagging (a high-temperature-resistant wrap) and should be monitored so that it never exceeds 200 degrees Fahrenheit. Dry exhausts need lagging, air gaps and proper support to minimize errant combustion, vibration or movement.

We suggest regular checks of engine hot spots with touchless pyrometers. Prices are reasonable for handheld thermal cameras, which can give an additional viewpoint of potential trouble. A quick scan will clearly show an exhaust hot spot or a potential problem inside an electrical component.

Cameras and remote temperature sensors can also add levels of security, since it can be a challenge to know what is happening in the engine room when you are underway.

And, no amount of fuel leak is acceptable. Fuel hoses have a life span that might be 20 or 30 years, depending on their environment, and they should be periodically inspected for cracks or damage. While the engine is at idle, trace the path of the fuel from the tank to the manifold, through the filters, onto the engine and back to the tank. Touch each fitting with a dry paper towel to be sure every fitting is leak-free.

Smoke Detectors

Marine-rated smoke detectors are wired to the ship’s DC system, so a failed 9-volt battery won’t interfere with them. Home-style smoke detectors or combination smoke and carbon-monoxide detectors also work on board as long as the batteries are checked and renewed at least yearly. Some smoke detectors can be programmed to link with other detectors aboard the vessel, creating ship-wide alarms. If the boat has Wi-Fi, then some smoke detectors will send alerts to a phone or computer. A multitude of remote boat-monitoring systems also have this feature.

Fighting Fire

Handheld fire extinguishers should be rated for the types of fires that may occur, and stamped “marine type.” They must be at least B-rated, but that does not mean they can’t be rated for other fires. A-type extinguishers are for solid combustible sources such as wood or paper. B-type extinguishers are for flammable liquid fuel sources. C-type extinguishers are for electrical fires.

U.S. Coast Guard rules delineate which boats are required to carry fire extinguishers, what type and size, how many per boat, and their placement. All fire extinguishers are stamped with a date on the bottom. Disposable fire extinguishers (generally those with plastic handles) should be replaced every 12 years. Others can be serviced, but it may be cheaper to replace smaller units. It’s best to have fire extinguishers recertified yearly.

Fixed fire-protection products from companies such as Fireboy-Xintex, Sea-Fire and others offer an additional level of protection. These systems typically have a bottle of firefighting agent mounted high in the engine room and sized for the space. The bottle will have a glass vial in the nozzle that, when broken, releases the agent. A remotely mounted pull handle can break the glass vial, or heat can break it automatically.

If the extinguisher were to be triggered while the engine, generator or blowers were running, much of the agent would be sucked through the air intakes and wasted. The solution to this problem is automatic shutdown devices that trip when the fire extinguisher is triggered. On larger yachts, the engine room air intakes will also need automatic louvers. There should be an override switch at each helm that shows that the bottle has discharged, and that allows you to restart the engine. In some navigational situations, it might be better to start the engine and go to plan B to fight the fire. There’s also recently USCG-approved technology from Stat-X, which uses aerosol canisters to suppress fires.

Boats fitted with lithium batteries have an additional risk, since conventional fire extinguishers may not put out this type of fire. Lithium fires are technically categorized as class B fires, but enough water will also put them out. Some designers are placing the batteries low in the boat and adding seacocks that can be opened to douse the bank. Better to flood a compartment than to have the battery burn a hole through the hull.

High-capacity washdown pumps can also be used to great effect, assuming the boat’s power is still working and the hose is long enough. Raw or freshwater spigots in the engine room and near the entrance can be used in an emergency too.

When fighting a fire, the correct type of extinguisher needs to be used, and the source also needs to be removed. For electrical fires, the breaker and battery switch may need to be turned off. Fuel fires need access to the fuel valves, including propane solenoids. Remote switches or valves can shine in this situation. If the fire is in the engine room, along with the fuel valves and battery switches, you may not be able to access them in an emergency.

Exit Strategies

At some point, the fire may be so out of control that you have to abandon ship. Ask yourself: Is there more than one way out of each compartment if a cabin door is blocked? Look around each compartment (especially sleeping spaces) and make sure you have a second way out. Do this for each guest as part of your orientation. Show them where the firefighting equipment and life jackets are located.

Also give some thought to life-raft accessibility. How hard will it be to launch the tender? One or the other should be able to deploy in a few minutes (possibly without power) along with a readily accessible ditch bag. If fire is the enemy, and the enemy is overrunning you, retreat may be the right option. Saving a boat is not worth losing your life. Not having to make that difficult decision in the first place is a much-preferred alternative.

This story was originally published in our sister publication, PassageMaker Magazine and appears in Soundings August 2023 issue.