Sailing Safety Guides

Fire Gas And CO

Fire, Gas And Carbon Monoxide On Board

Fire, gas and carbon monoxide are frightening because they can grow faster than the crew understands what is happening.

A boat is a small living space with fuel, batteries, chargers, cooking, engines, exhaust, wiring and sleeping people close together.

High-Stress Use

Fire, gas or CO: isolate first, then fight if safe

A boat fire grows fast because space is small and escape options are limited. Isolation and crew safety come before saving equipment.

First 30 seconds

Shout the alarm and get everyone awake and moving.
Stop cooking, engine and non-essential electrical loads if it is safe to reach the controls.
Keep an escape path behind you before opening a hot or smoky space.

First 5 minutes

Close gas at the bottle, isolate batteries or shore power, and use the correct extinguisher.
Call Mayday if fire is not immediately controlled or smoke is spreading.
Move lifejackets, grab bag, EPIRB and liferaft readiness forward in the plan.

When stable

Watch for re-ignition and hidden heat behind panels.
Ventilate CO only when it is safe and does not feed a fire.
Do not restart electrical systems until the fault is found.

First Principle

The first warning may be small

A faint gas smell, a warm cable smell, a charger that sounds different, a CO alarm, or a crew member with headache and confusion can be the first sign of something serious.

Do not explain it away too quickly. On a boat, the source may be hidden behind panels, under bunks, in the engine space or inside a locker. By the time flames or thick smoke are obvious, the easy minutes may already be gone.

Fire risks

Fire on board often starts with ordinary systems: wiring, batteries, chargers, inverters, galley flame, heaters, fuel or engine exhaust. The danger is not only flame. Smoke, toxic fumes and loss of control can become the bigger problem.

Wrong cable size or fuse size.
Loose high-current battery or inverter connections.
Chafed positive cables near metal or engine parts.
Overheated chargers, inverters, alternators or lithium battery systems.
Cooking flame, hot oil, towels or curtains near the galley.

Gas risks

LPG is useful, but it is heavier than air and can collect low in the boat. A small leak can become dangerous if it reaches the bilge or an enclosed space.

Close the bottle valve when gas is not needed.
Keep gas bottles in a proper drained locker.
Inspect hoses, regulators and clamps regularly.
Use a gas alarm if fitted, but do not let the alarm replace your nose and discipline.
If gas is suspected, ventilate naturally and avoid switches, sparks and flames until safe.

Carbon monoxide is different

Carbon monoxide, often written CO, is especially dangerous because you cannot see it, smell it or taste it. It can come from engines, generators, heaters, stoves, exhaust leaks and poor ventilation. It can affect people in the cabin, cockpit or under covers depending on the airflow.

The symptoms can look like seasickness, tiredness, alcohol, flu or poor sleep: headache, dizziness, weakness, nausea, confusion and unusual behavior. If several people feel wrong at the same time, take it seriously.

Install CO alarms near sleeping areas and according to manufacturer guidance.
Test alarms at least every week, and replace them before expiry.
Do not run engines, generators or heaters with known exhaust or ventilation problems.
Be careful with cockpit enclosures, aft cabins and following wind that can bring exhaust back on board.
If a CO alarm sounds, move people to fresh air first, then investigate.

If you smell gas

Do not light anything.
Do not operate electrical switches if gas may be present.
Close the gas bottle valve if safe to reach.
Ventilate the boat low and high.
Get people out of the cabin air.
Find and fix the source before using gas again.

If you smell burnt plastic

Stop non-essential electrical loads.
Disconnect battery banks if safe and if the boat can still remain safe.
Check the places where high current or charging normally happens first: battery compartment, main switches, main fuses, busbars, inverter, charger, solar controller, shore-power/AC panel and DC switch panel.
If the engine is running or has just been running, also check the alternator and its cables on the engine.
Check any recent electrical work or newly fitted equipment early. A new cable, connector, fuse, charger, pump or instrument is a natural suspect until proven safe.
Feel near cables and equipment carefully, without burning yourself or touching live parts.
Do not just reset a breaker or replace a fuse without finding the reason.

First actions if there is fire

Fire decisions are fast. The skipper must protect people first, then fight the fire only if it can be done without trapping crew or losing the only escape.

Shout the alarm and get lifejackets on if abandoning may become possible.
Move people away from smoke and toxic air.
Stop the source if safe: gas bottle, engine, battery switch, charger, inverter or fuel.
Use the correct extinguisher or fire blanket if the fire is small and reachable.
Close openings only if it helps contain the fire and does not trap people.
Call for help early if the fire is not immediately controlled.

A small contained fire may be fought. A growing fire in a hidden locker, battery area or engine space can become an abandon-ship situation very quickly.

Equipment should be reachable

Fire extinguishers near cabin exit, galley and engine access.
Fire blanket near the galley, not behind the flame.
Gas shutoff understood by crew.
Battery isolation reachable and labelled.
CO and smoke alarms tested.
Knife, torch and handheld VHF accessible if smoke fills the cabin.

Do not create a second emergency

While dealing with fire or gas, the boat may still be moving, drifting or sailing. Keep the whole situation in mind.

Check traffic, shore, rocks and sea room.
Slow the boat or heave-to if that makes the situation safer.
Keep one person responsible for navigation and radio if crew is available.
Prepare liferaft and grab bag if the fire is not under control.

Printable fire, gas and CO location cards

I have added a printable "where is everything?" card sheet for fire, gas, carbon monoxide and electrical isolation. It is meant to be filled in for the boat, printed, laminated, and placed where crew can read it quickly.

The cards cover fire extinguishers, fire blanket, gas shutoff, alarms, battery banks, main switches, main fuses, busbars, inverter, chargers, shore power, solar controller, high-load breakers, engine/generator controls and crew roles.

Open Fillable Fire/Gas/CO Cards Open Blank PDF

Engine-room fire

An engine-space fire is not a place for curious looking. Opening the hatch can feed the fire with oxygen and push smoke into the cabin.

Stop the engine if safe, close fuel supply if possible, and keep people out of smoke.
Use the fire port or fixed fire system if fitted, following the boat's system instructions.
Do not open the engine cover just to check whether it worked. Wait until heat and smoke are clearly controlled.
Prepare to call for help and prepare abandon-ship gear if the fire is not quickly contained.

CO around exhaust, generators and covers

Carbon monoxide can build when exhaust is blown back into the boat, when a generator runs near an opening, or when cockpit covers trap bad air. The risk can exist even without visible smoke.

Never run portable fuel-burning equipment in enclosed boat spaces.
Be careful with following wind, cockpit tents, aft cabins and swim platforms near exhaust.
If several people feel headache, dizziness or unusual tiredness, move to fresh air first.
Treat CO alarms as real until proven otherwise.

After an alarm or incident

Do not return to normal just because the smell is gone or the alarm stopped. Find the cause.

Ventilate thoroughly.
Inspect wiring, insulation, nearby wood, foam and hidden spaces.
Check battery boxes, fuses, busbars, chargers, alternator and inverter connections.
Inspect gas hoses, stove, regulator, locker drain and shutoff.
Check engine and generator exhaust system before running again.
Replace discharged extinguishers and document what happened.

How this connects to SailingKSF

This guide sits beside the electricity and power articles. The technical details matter because a bad installation can become a fire. But the skipper also needs simple emergency habits: believe the warning, protect people, stop the source and call early if the problem is growing.

Electricity On Board Power And Battery Safety Calling For Help At Sea

USCG carbon monoxide and boating - Official carbon-monoxide safety page for boaters. CO cannot be seen, smelled or tasted, so alarms and ventilation matter.
BoatUS Foundation fire extinguishers - Plain guide to extinguisher requirements, inspection, storage and basic use on recreational boats.
IMO SOLAS Convention overview - International background for ship safety, life-saving appliances and GMDSS. Mostly commercial-vessel context, but useful for understanding the framework.
USCG Boater's Guide to Federal Requirements - Official United States recreational boating equipment guide. It is US-specific, but useful as a clear example of minimum-equipment thinking.
RNLI yacht sailing and motorboating safety - Practical safety advice from a rescue organization, useful for thinking about lifejackets, calling early, preparation and what rescuers need from you.
UK Marine Accident Investigation Branch - Official accident reports and safety digests. Useful for seeing how small decisions, gear failures and fatigue can grow into serious incidents.

App Connection

Use this together with KSF Passage Companion

The articles are easier to use on a real boat when your own boat details are already written down.

Store where safety gear, tools, spares and manuals are located.
Keep boat-specific checklists for night, heavy weather, departure and emergencies.
Use logbook notes for failures, chafe, repairs and weak points that should be checked again.

Open Passage Companion Open Printable Cards

Feedback For Fire Gas And Carbon Monoxide On Board

If you have practical experience with boat fire, LPG, carbon monoxide, alarms or electrical faults, I would be glad to read what should be added.

No public comments yet. You can be the first to add feedback.

Treat strange smells and alarms as real

Burnt insulation, gas smell, smoke or a CO alarm should stop normal life on board until the source is understood and the crew is safe.