Refuelling a boat safely

A marina fuel dock is a busy, cramped place where boats, people and flammable liquids meet. Most refuelling goes smoothly, but when it goes wrong, it can go very wrong: petrol vapour that collects in a bilge can ignite with a spark from a starter motor or bilge pump. Transport for NSW's onboard fuel brochure calls refuelling one of the most potentially hazardous parts of boating, and says the risk is greatest with inboard petrol engines. This guide sets out a refuelling routine based on official advice from Transport for NSW and Maritime Safety Victoria.

Why petrol is the big risk

Transport for NSW explains that petrol has a much lower flashpoint than diesel and its vapours ignite far more easily. Petrol fumes are denser than air, so they sink and collect in the lowest parts of a boat, such as the bilge and engine bay, if those spaces aren't ventilated. If there's an ignition source, the fumes can easily explode. The main risk is during or just after refuelling, but a fuel leak can create the same danger at any time.

Diesel is less volatile, but it's still flammable, slippery and polluting. Treat every fuel with care.

Before you refuel

Transport for NSW and Maritime Safety Victoria's advice combine into a simple checklist:

• Switch off engines and electrical equipment.
• Moor securely against the jetty, wharf or shore, and don't let another boat tie up alongside you while you refuel. Avoid tying up alongside a boat that's refuelling.
• Get everyone off. Maritime Safety Victoria says no passengers are permitted on board during refuelling or restarting.
• Remove ignition sources. Put out cigarettes and turn off pilot lights, gas fridges, electrical equipment and mobile phones.
• Close hatches and doors so fumes can't drift into cabins and enclosed spaces.
• Know your fire extinguisher: have the right equipment aboard, easy to reach and in working order, and know where the fuel dock's equipment is.
• Read the instructions at the fuel facility, such as using anti-static earth wires.

Check you know your tank's capacity and how full it is, so you don't overfill. And make sure you've selected the right fuel for your engine before you start.

During refuelling

• Put the nozzle in the tank before starting the dispenser.
• Keep firm contact between the nozzle and the filler neck to avoid static sparks, and keep your feet firmly on the deck, wharf or pontoon.
• Always operate the dispenser by hand. Never lock or jam it open.
• Don't overfill. Transport for NSW notes that fuel expands in high temperatures; leave room in the tank.
• Try not to spill any fuel. Turn off the dispenser before removing the nozzle.
• Have absorbent material or a rag ready to clean up drips straight away.

Stay focused. Transport for NSW advises taking care, following the correct procedures and not being rushed or distracted by others.

After refuelling

This is the step people skip, and it's the one that matters most for petrol boats.

1. Replace the fuel cap.
2. Open all hatches and doors and make sure the engine bay and bilges are ventilated.
3. Run the bilge blower. Transport for NSW says to run it long enough to clear fumes, depending on the blower's capacity and the size of the engine space.
4. Check the bilges for spilled fuel. If there is any, clean it up with fuel-absorbent material, or pump it into a container or onshore tank, then ventilate.
5. Sniff for fumes. Transport for NSW suggests using your sense of smell along with a suitable gas detector to find pockets of petrol vapour. Remember fumes collect in the lowest part of the boat, which can change with how the boat is loaded.
6. Start the engine only when you're satisfied the boat is free of fumes. Maritime Safety Victoria says don't start the engine if you can detect fumes.
7. Let passengers board only after the engine has run for several minutes, as Transport for NSW advises.

Then move off the fuel berth. Transport for NSW says not to stay alongside a refuelling facility longer than necessary; if you want to load supplies and gear, move somewhere else.

Portable tanks

Many small boats use portable fuel tanks. As well as the steps above:

• Fill portable tanks away from the boat, in a well-ventilated, no-smoking area, so fumes don't build up around the boat.
• Use a wide-mouthed funnel if you need one, and clean up splashes straight away.
• Check the tank's breather for defects regularly.
• Take care lifting heavy tanks aboard, and get help if needed.
• Secure tanks so they can't move while under way.
• Use fuel lines to transfer fuel rather than pouring it through a funnel or spout where possible.
• Keep spare fuel in a tightly capped, secure container.

Look after your fuel system

Refuelling safety starts long before you reach the fuel dock. Transport for NSW recommends:

• having the engine, electrical and fuel systems serviced regularly by a qualified person;
• inspecting the fuel system often for leaks, especially hoses, joints and clamps, and considering double clamping;
• fixing leaks before starting the engine, and shutting down as soon as possible if you find one while running;
• keeping the engine, fuel lines and bilges clean so leaks are easy to spot;
• keeping ignition sources out of low, enclosed spaces with fuel system parts, and using spark-protected equipment where electrical items must be there;
• considering fuel or LPG vapour sensors and alarms.

Maritime Safety Victoria adds: check perishable fuel lines for wear and carry spares, and don't keep oily or fuel-soaked rags aboard.

Spills

Fuel on the water harms wildlife and is an offence in most places. Most fuel docks have spill kits; find the nearest one before you start, and consider carrying a small kit aboard. Clean up small spills immediately, and tell marina staff about anything larger.

If there's a fire

Get everyone off and away, raise the alarm and call 000. Use an extinguisher only if it's safe and the fire is small. Never go back aboard a burning boat.

Diesel boats

Diesel's higher flashpoint makes it less likely to ignite than petrol, but the basic routine is the same: engines off, boat secured, no ignition sources, no overfilling and spills cleaned up. Diesel also degrades and attracts water and microbial growth, so keep tanks topped up when the boat is laid up and consider a fuel/water separator.

Key points

• Petrol vapour collects in bilges and can explode; refuelling is the riskiest time.
• Engines off, boat secured, passengers off, hatches closed and ignition sources out.
• Keep the nozzle in firm contact, operate it by hand and don't overfill.
• Afterwards, open up, run the blower, check for fumes and spills, then start.
• Fill portable tanks away from the boat and maintain your fuel system.