Most sailing yachts don’t carry enough fuel to motor across an ocean. Even having a range of half the distance, so that you could reach one side or the other, is a luxury most skippers won’t have. A significant proportion of any ocean passage will need to be done under sail and careful attention given to routing to avoid being becalmed.

Calculating motoring range, planning engine use for areas of variable winds, such as the ITCZ (Inter Tropical Convergence Zone), and deciding how much fuel to carry, are an essential part of passage planning.

But even the best laid plans can go out of the porthole during an ocean passage. Accelerated wear and tear makes rig failure an ever-present threat on long passages. While anyone setting off across an ocean should be prepared for self-sufficiency, problems with the diesel supply on board, combined with light airs, could make a fuel transfer from another vessel a pragmatic solution.

Or, of course, you might be nearest to another vessel that requires a top-up. It’s a scenario which is more common than you think, and one which we’d do well to prepare for.

Take Off was dismasted in the 2022 ARC. In calm conditions, crew swam to retrieve the fuel canisters. Photo: Alex Tucker/Voyager II

Fuel consumption

When Jayne Toyne and her co-skipper Marina Foti were dismasted during the 2019 AZAB aboard her Dehler 36, Boogie Nights, she had the advantage of knowing her boat inside out.

“I knew exactly how much fuel the engine uses,” she said, “and we would have just made it the 400 miles to Ponta Delgada on what we had”. But having just had one catastrophe, she wasn’t taking any more chances, so when the coastguard diverted a container ship to offer her more fuel, she gratefully took the opportunity of taking on more.

On a dismasted vessel engine failure as you make landfall could be catastrophic, so when every litre counts, maximise range by reducing electricity consumption, slowing down and creating a jury rig if possible.

Communications

If the rig has been damaged, then the chances are the communication systems have been too. Before a fuel transfer can commence, the casualty needs to raise the alarm and the rescue party needs to find them – all easier said than done if the masthead VHF antenna has been lost.

a cockpit full of fuel cans was a saving grace for Jayne Toyne and Marina Foti on Boogie Nights. Photo: Jayne Toyne

While fuel supply issues don’t usually warrant a distress signal, in the case of a dismasting these may be the only communications left available. When California Clipper rolled and dismasted in the North Pacific during the 2009/10 edition of the round the world yacht race, the majority of the comms equipment was destroyed by water ingress.

The US Coast Guard responded to their EPIRB activation and overflew them, dropping a handheld VHF in a floating container. However, it took 18 hours before another member of the Clipper Race fleet, Jamaica Lightningbolt Clipper, reached them to provide a comms relay and transfer supplies.

“We spent hours searching in the area where they were supposed to be,” recalls Jamaica Lightningbolt skipper, and now director of PSA Prime Marine, Pete Stirling. “All we had to go on was the EPIRB positions relayed from Falmouth Coastguard”. A fully charged handheld VHF and SART, or AIS-enabled EPIRB, stowed in a drybag will come into their own in these scenarios.

Fuel cans being hauled in to Boogie Nights after being dropped from a container ship. Photo: Jayne Toyne

Making the transfer

Once the two vessels are in contact with each other, there needs to be a clear plan of action as to how to make the transfer. There are two options: a boat-to-boat transfer keeping the jerry cans suspended between the two vessels, or dropping them off for the casualty to collect.

Boat-to-boat transfer method

In calm conditions passing the jerry cans across on a long line between two vessels is possible. Lash or cable tie the jerry cans to the transfer line so that they can be easily cut free. If you can prevent them from entering the water they’re easier to retrieve, and there’s less risk of water ingress, but this technique needs careful co-ordination between the helms and several good deck crew.

After dismasting in the ‘Roaring Forties’ in the Global Solo Challenge, Ari Känsäkoski was transferred fuel and provisions from a Japanese fishing vessel, and then by a RORO ferry under delivery, enabling him to sail 1,200 miles under jury rig. Photo: Global Solo Challenge

Collection method

In big seas any kind of boat-to-boat transfer becomes difficult and even dangerous, especially on a dismasted vessel which can have a violent motion. Fortunately diesel is lighter than water and if the jerry cans are only partially filled they float well. Ensuring that they’re properly sealed, they can be daisy-chained onto a long line (ideally a floating line) and deployed into the water for the casualty to collect. Adding a fender onto the end as a float will make them easier to retrieve using a boat hook and a couple of fit crew members.

Transfer from a merchant ship

It may well be a merchant ship, rather than a yacht, which offers assistance mid-ocean. When Jayne Toyne received the fuel transfer from a container ship, they used a carefully co-ordinated manoeuvre in which the container ship slowed right down to provide a lee for Boogie Nights to approach. They sent down a long heaving line which Toyne took aboard, and then payed it out as the yacht pulled off.

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Boogie Nights then pulled away and the ship deployed a string of four, partially filled, jerry cans over the side which Toyne hauled in. “It was really tiring”, she reflected, “especially after dealing with the dismasting.”
Large ships run off a heavier grade fuel than marina fuel but they will often have a supply of lighter grade diesel for auxiliary machinery such as generators. Toyne was alarmed to find that this was black-coloured, so she diluted it as best as she could with the diesel she already had in the tanks, and the engine ran perfectly well on it.

Throw bag

A throwing bag is one of the most under-appreciated items on the boat and comes into its own for transferring supplies. Use them to establish a connection with the other vessel, before sending a heavier line across. Make sure the crew all know how to use it and repack it.

A throwing line is the first step to establishing a transfer line. Photo: Clipper Ventures PLC

Line handling

Good line handling is essential for safe transfers at sea. Crew must be briefed to let go of a line if needed, and should never stand on any lines. Don’t be tempted to make fast lines between the vessels. You might need to be able to pull away from each other if a large wave comes and any snatching could cause the line to part, creating a dangerous ‘snap-back’ zone.

Jerry cans

Fuel can’t be transferred at sea without a decent set of jerry cans. As the casualty vessel you might need to send over some jerry cans to be filled, rather than rely on the other vessel to provide them, so empty any full cans that you have into the tank in case the donor vessel doesn’t have anything suitable.

When buying jerry cans go for something simple and robust. In my experience complicated adaptations to make them easier to pour just make them more likely to leak.

Invest in a jiggle hose (£15 from B&Q). Consisting of a small pump on the end of a hose, when the hose is shaken they create a siphon and start to transfer the liquid from one container to another. They’re the only sensible way of getting fuel from a jerry can into a deck filler at sea.

A decent set of jerry cans is essential. Photo: Louise Wennberg/Take Off

In the event that the fuel tanks have been damaged or contaminated, being able to run the engine from a jerry can is a useful get-out-of-jail card. It’s worth spending time looking at your fuel system to work out how you’d do this.

In most cases you’ll need two lengths of the right diameter fuel hose, so that you can secure the jerry can somewhere safe and connect it to the feed and return points on your engine. The engine circulates much more fuel than it burns, so it will quickly empty a jerry can back into the tank if you haven’t rigged the return to it as well.

Deck fillers

Deck fillers are a possible point of entry for water into fuel tanks. Check the condition of the O-rings before setting off on green water passages. If bound for less hospitable corners of the globe consider removing them entirely and putting a fill point directly on the tank inside. It’s more awkward to fill up, but reduces the chances of catastrophic saltwater ingress.

Full and provisions with Ari Känsäkoski enabling him to sail 1,200 miles under jury rig. Photo: Global Solo Challenge

Conclusion

There’s no right or wrong answer as to how much fuel to carry. You can strap the jerry cans to the transom and bunker up for every eventuality but you’ll make the boat heavier – and more reliant on the engine – and may compromise stability in doing so. Keeping weight to a minimum maximises light airs performance but reduces your options in an emergency. How much fuel to carry for an ocean passage will depend on the boat, the crew, and the route.

In most cases we have to compromise somewhere in between maximum and minimalist approaches. While carrying exactly the right amount of fuel isn’t always possible, carrying the right equipment for a fuel transfer is.

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