Propane is the cooking fuel on the majority of cruising sailboats worldwide, and for good reason. It is available in virtually every port from the Caribbean to the Pacific, it burns cleanly and efficiently, and a 20-pound tank lasts a typical cruising couple four to six weeks. The cooking experience aboard a propane-equipped boat is indistinguishable from a good domestic gas range — better, in fact, because the burners on dedicated marine stoves tend to be hotter and the gimbaling means you can cook a proper meal in a seaway.
The problem with propane is physics. LPG — liquefied petroleum gas, which includes both propane and the butane blends sold under local brand names in Europe — is significantly heavier than air. When it leaks, it doesn't dissipate upward like natural gas; it sinks. It flows to the lowest point available, which on a boat is the bilge. There it accumulates invisibly, odorlessly in the early stages, until some ignition source — the engine starter, a light switch, a running bilge pump — provides a spark. The resulting explosion is not a house fire; it is rapid and structural.
This is not a theoretical risk. Boats have been destroyed by LPG bilge explosions. The safety standards that govern marine LPG installations exist because of documented incidents, and the requirements — solenoid valve, sealed vented locker, rated hose — are the minimum acceptable installation, not excessive caution.
The Solenoid Valve: Why It's Mandatory
The solenoid valve is an electrically operated shutoff installed in the gas line at or immediately after the tank. When you finish cooking, you close the solenoid from a switch at the galley. The gas line from the solenoid to the stove depressurizes: the gas in that line burns off, the flame extinguishes, and there is no pressurized gas anywhere in the boat's interior. If the stove develops a leak overnight, nothing escapes.
Without a solenoid valve, the only way to shut off the gas supply is to walk to the cockpit locker, open it, and manually close the tank valve. In practice, this step gets skipped when you're tired, when it's raining, when the boat is rolling. A solenoid valve with a galley-mounted switch costs roughly $120 and removes the human failure mode from the system. ABYC Standard A-1 requires a remote shutoff valve on every marine LPG installation for precisely this reason.
The solenoid valve requires a 12V connection. The switch at the helm or galley is wired in series with the solenoid coil. Most installations also include an LED indicator at the switch so you can see at a glance whether the gas is on or off — important on a boat where a crew member unfamiliar with the system might be in the galley. Some owners wire the solenoid through a bilge gas detector so that an LPG alarm automatically shuts the valve. This is belt-and-suspenders safety but not required.
The Sealed Vented Locker
LPG tanks aboard a boat must be stored in a dedicated locker that is gas-tight on the cabin side and drains overboard. The gas-tight separation from the cabin ensures that any tank leak — a slow seep from a valve fitting, a momentary overflow when connecting a new tank — cannot migrate below decks. The overboard drain, sized to pass the maximum likely gas flow from a catastrophic valve failure, allows any accumulation to exit the boat harmlessly.
The locker design requirements are specific: the drain fitting must be at the bottom of the locker, the drain line must not have any low spots that could trap liquid (and thus block gas flow), and the drain exit through the hull must be above the waterline at all heeling angles. A locker whose drain exits below the heeled waterline will fill with seawater when sailing — this is a common installation error on boats where the tank locker is in a cockpit seat that heels close to the water.
The locker lid must seal against the cabin. This typically means a rubber gasket around the lid perimeter, similar to a deck plate seal. The seal doesn't need to be airtight for all normal conditions — it needs to prevent gas accumulation from flowing below decks. Inspect it annually for cracking or compression set; a failed gasket is invisible until you have a leak.
Storing a propane tank in any other location — a cockpit locker that opens to the cabin interior, the anchor locker, under a settee — is dangerous regardless of how convenient it seems. The physical separation from the cabin interior is the only thing that makes the system safe when the tank leaks, and it will eventually leak, even if only briefly when connecting or disconnecting.
Hose Specifications
The flexible hose connecting the regulator to the stove — or between the solenoid valve and the stove if the solenoid is at the tank — must be rated for LPG service. Standard rubber hose, fuel hose, and general-purpose tubing are not acceptable. LPG-rated hose is manufactured with a specific inner liner that resists permeation by LPG and does not degrade from the gas's solvent properties. It is marked with its rating and typically has a yellow or orange tracer or outer jacket.
Replace LPG hose every 5 years regardless of appearance. Hose that looks fine externally may have degraded internally — the liner cracks from ozone exposure and fatigue in ways that aren't visible from outside the hose. The cost of a hose replacement is trivial compared to the consequence of a hose failure that puts gas in the bilge.
Inspect the hose connections at both ends annually. The fittings should be tight, with no evidence of corrosion on the brass fittings or abrasion on the hose cover. Apply a mixture of dish soap and water to every connection and look for bubbles when the gas is on — a bubble-forming connection is leaking and must be addressed before further use. Leak detector sprays are available at propane suppliers and are more sensitive than dish soap.
Regulators and the Atlantic Crossing Problem
The regulator reduces tank pressure (typically 100–200 psi from a full propane tank) to the working pressure the stove requires — roughly 11 inches of water column (0.4 psi) for North American appliances or 28–37 mbar for European equipment. The regulator's inlet fitting must match the tank valve.
In North America, the standard connection for large tanks (20 lb and up) is the POL fitting — a left-hand threaded male connection that screws into the tank valve. The POL is also called a CGA 510. For smaller portable tanks, the Type 1 or ACME fitting is standard. If your regulator has a POL fitting, you can use virtually any propane tank in North America without an adapter.
In Europe, the LPG market is a patchwork of national standards. The UK uses Calor Gas fittings with clip-on connections incompatible with North American POL. France uses Butagaz. The Mediterranean islands use a variety of local fittings. Campingaz has a pan-European clip-on system that is widely available but uses a different pressure and different appliance fittings than standard marine propane equipment. An Atlantic-crossing boat that arrives in the Azores or Canary Islands with a North American POL regulator will spend time hunting for an adapter.
The practical solution: carry a small set of adapters before crossing the Atlantic. A Campingaz clip-on adapter (used with their blue 907 and 904 cylinders, widely available throughout Europe) and a generic European screw thread adapter (for Spanish and Italian cylinders, which often use a thread fitting similar to Calor) cover the majority of situations. Some cruisers install a spare regulator body with European inlet fittings for extended Mediterranean use. The adapters are available from UK chandleries before the crossing; they are difficult to find in North America.
LPG vs. CNG: The Safety Comparison
Compressed natural gas (CNG) is safer than propane in the specific scenario that matters on a boat: leaks. Natural gas is lighter than air — if it escapes in the bilge, it rises and disperses rather than pooling and accumulating. The explosion risk from a CNG leak is significantly lower than from an LPG leak.
The problem with CNG for world cruising is availability. CNG filling stations exist in North America — primarily in the Pacific Northwest and Florida — and in a handful of other locations globally. They are essentially absent from the Caribbean, the Mediterranean, the Pacific islands, and most offshore cruising destinations. A boat that commits to CNG commits to a fuel system that will require creative solutions or significant inconvenience outside of North America.
Propane is available everywhere. In the most remote Pacific anchorage, if there is a settlement with cooking facilities, there is propane. The global distribution network for LPG, driven by domestic cooking demand, is one of the most reliable supply chains in the world. For a cruising boat that intends to leave North American waters, propane wins despite its heavier-than-air characteristic — because the answer to that risk is correct installation, not a different fuel.