How to get your yacht home without power

Jan 23, 2024

Electrical failure can put you in the dark when your instruments go down. A few traditional skills, and a good tool kit, can see you safely home, says Pete Goss

Electrical systems and electronics have become such an essential part of our normal lives that it’s hard to imagine life without them. Those good old days when there was a map in the glove box, awareness of the sun’s location and a dinghy compass glued to the dashboard of the family car are becoming a dim and distant memory. Amazingly it’s not even a memory for the younger generation who look at a map as if it’s an Egyptian parchment that requires mystical alchemy to decipher the direction of travel.

The sophistication that has recently become the norm on standard yachts is quite extraordinary. Chart plotters, AIS, radar, wind instruments, Bluetooth windlass controls, chain counters, fridges, freezers, heaters, hot and cold running water, USB points, satcoms, underwater lights, electric outboards, water makers, even night vision systems. All wonderful bits of kit but of course, if we’re honest, none of them are essential.

I know this thanks to our recreation of the voyage of the Mystery from Cornwall to Australia in a 37ft Mounts Bay Lugger, an adventure that took us halfway round the world and deep into the Southern Ocean where we were rolled upside down. Amazingly we had very few problems and none of them electric for there’s a reliable beauty in simplicity. If it’s not there to go wrong it won’t go wrong.

Any kind of headmark will help keep a steady bearing, though check the compass regularly if using a heavenly body, and don’t forget about tidal set. Photo: Richard Langdon

We cooked on gas, used oil lamps for lighting and steered by hand under the guidance of compass and sextant. Progress was measured by a Walkers Log gifted by my late friend Vikki Penney. Without the stress of waiting for a complex system’s next failure it became a simple, wholesome voyage that was far more rewarding as we relied on fundamentals that have served mariners for generations. Of course we carried a handheld GPS for safety and used it regularly in the leaden Southern Ocean skies.

Once comfortable with the fundamentals of how to sail and navigate without electronics, the critical aura of all other equipment evaporates to become a non- essential aid. Practising the fundamentals is essential in keeping this rightful order. It’s a skill that doesn’t have to be perfect, it just has to be safe.

While modern electrics and electronics are so much more reliable than their forebears, and back-up systems such as handheld instruments, phones and tablets are cheap and plentiful, it still doesn’t make you immune to being left in the dark. A lightning strike, a simple alternator failure, an engineroom fire, contaminated fuel putting the engine out of order, or just a software glitch… the potential sources to make you go ‘dark ship’ are plentiful, and well within the realms of common cruising experience.

Paper charts, pencil, plotter, dividers are all you need. A long ruler and a pair of compasses, as well as a sharpener and eraser make life easier too. Photo: Theo Stocker

It may seem obvious but start by sailing in the general direction of your destination. It’s easy to lose your bearings initially when the instruments you’ve been usedto relying on are no longer talking to you. Use your compass, the stars, wind or whatever else is at hand, from a city’s loom at night to following the cross-Channel ferry. Provided you can measure the depth with a lead line you’ll be fine.

Even thick fog loses its menace as you follow a contour or drop the anchor at a safe depth to wait for more clues to reveal themselves. Knowledge and the patience to wait for safety to come to you isn’t as intuitive as it might be in this data-driven world. Heaving to for a think and a cuppa is a wonderful option that’s always been there for the taking.

A simple head torch has multiple uses when the power goes. Photo: Fox Morgan

As with most things in life, staying ahead of the curve is the petri dish of safety. Given that power loss comes without warning, a detailed log and an hourly GPS fix on the chart will provide a clear point from which to project traditional navigation.

It goes without saying that a good almanac with tidal information should be on the shelf along with the tools of the trade from pencils to Breton plotter and dividers. Work out a simple shaded system that allows your head torch to become a compass light. Be minded that you need to keep it far enough away to avoid affecting the compass heading.

A system like this served me well on a Biscay passage. A leadline is also a useful thing to have on board for a number of reasons, not least taking soundings the old-fashioned way. They’re easy to make up with a marked line and a weight heavy enough to sink the line quickly.

There’s a skill to getting an accurate reading from a hand bearing compass on a moving boat that needs practice

The absolute basics might keep you safe but they won’t necessarily get you to your destination. This calls for precise navigation and enough experience to factor in intuitive things like your vessel’s leeway on different points of sail and the effect of varying weather and waves on your heading.

I’m assuming that most people who put to sea have a basic understanding of navigation but this can fade through lack of practice as electronic chartplotters fill the breach. Use the winter to sign up for an RYA Coastal or Offshore evening class as a refresher. Periodically cover up the plotter and navigate traditionally; doing so is fun, rewarding and prepares you for that day when everything crashes.

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Get familiar with three point fixes, running fixes, dead reckoning and estimated position. If you don’t have a Walkers Log, practise estimating your boat speed; with time it’s amazing how accurate you can be.

On loss of power and needing to change over to traditional methods of navigation, revisit your passage plan and modify it accordingly. You might add a slight diversion to close a headland or other geographic reference to tighten your position. If visibility is good and you have a radio that still works, you might choose to close a shipping lane so as to call a friendly ship by VHF for a position check.

If you’re in a busy area like the Dover Straits you can call up Dover Coastguard and they will ask to make some dramatic course changes so they can identify you on radar and pass on your position. Scan the chart for a convenient diversion to get repairs or perhaps anchor in a safe bay to avoid night sailing if you’re not confident. Consider slowing down or heaving to so that harbour approaches are made in daylight and at high tide.

If you have a working handheld VHF radio on board, close the land to get within radio range. You may even be able to request position information, or more easily fix your position from landmarks. Photo: Mark Dyball / Alamy

While modern instruments have allowed us to see our cross track error to within millimetres, we’ve lost the art of making a landfall. Striking the coast a mile or two uptide of your final destination gives you room to be swept in, rather than pushed away from your desired harbour. Identify what landmarks you’ll be able to see, and avoid harbours that are difficult to pick out from seaward or have restricted access.

It’s certainly time to sharpen the pencil and tighten your relationship to navigation. If you’re a bit rusty pull out an RYA navigation booklet from your bookshelf to brush up on the basics. Change the watch system so that you as skipper, or a designated navigator can fully focus on navigation. It’s time for detailed tidal vectors and encouraging the crew to really focus on holding the course; something, thanks to autopilots, that is becoming a lost skill. Expand your passage plan by calculating tidal heights for the secondary ports along your passage. Add this to your navigation notes for each harbour along the way with points on markers, harbourmaster VHF channel and mobile number including a sketch of approach bearings and transits.

Tidy up the wiring behind your switch panel, and fit trip switches if possible to make solving electrical problems easier. Photo: Theo Stocker

The first rule of a power failure is not to have one and there’s lots of preventative measures to hand. Spread your sources of power across a number of technologies. On Oddity we have the main engine alternator, a wind generator and solar panels with the option of hydro generation if we go ocean sailing.

Make sure your engine is serviced and do your daily checks to include alternator belt tension and running your eye over all connections to see if there is any furring or corrosion. Have your batteries tested at the start of the season because old batteries are a common point of failure.

Electrical systems are often overwhelmed as additions start to draw down more power than their original design. In this instance it’s worth upping the supply wire to the control panel. Is your battery capacity adequate? It’s easy to work out once you have established the total draw of all your systems. Does your main breaker switch allow you to connect both the domestic and engine battery banks to either start the engine or prolong your supply? Get your wires tested as they can start to degrade quickly after about 10 years. If you need to replace wiring make sure you use tinned wire.

Spend a day following all wires through the boat and locating any hidden fuses so that when a failure arrives you are not starting out with a ton of confusing spaghetti that disappears to unknown locations. Tidy up the switch panel and put labels on all wires as they progress through the boat. Tug at or agitate all connections and replace any dodgy ones.

I like to update all inline fuses with waterproof blade fuses and often tape a spare fuse close by. Draw a wiring diagram of the boat so that you have something to refer back to. If you don’t have one I would highly recommend a battery monitoring system to keep you abreast of where things are.

If you have a charging issue the immediate action is to conserve what you have in the batteries for essential use. Turn everything off apart from your electronic navigation system. If you can turn non-essential elements of your system off, do so.

Put a fix on your chart and stream the Walkers Log instructing the crew to regularly check for weed getting tangled in the impeller. Turn off the autopilot as this pulls a big draw. If it’s not already dark prepare for night sailing by fitting the spare battery-powered navigation lights and set up a compass light. A head torch works well for this, or a cheap keyring torch with the lens coloured with red pen can work well too, as long as it doesn’t cause magnetic deviation.

If you don’t already have a list of the power consumption of each of your systems (a good thing to have and an easy winter job) use the manuals to work out your reduced consumption, check the power left in the system and calculate if you have enough to get home. Nine times out of 10 you’ll be fine but if you’re not, shut the whole system down with the main breaker switch.

You can always flash it up at each watch change to offer a good fix and conserve power for the final approach. As a guide, electronics shut down as low as 10.5V, and a lead acid battery will be dropping below 50% state of charge when the voltage gets to 12V, so 12V or slightly higher is a good point to set the alarm.

An analogue trailed log is a useful bit of kit to keep on board for accurate navigation without electronics. Photo: Richard Langdon

Once you’ve tightened up your navigation and settled the boat and crew into the new circumstances it’s time to establish the problem. If you’re lucky you might have a crew member that has some expertise but if not it’s important to hand over responsibility for safety of the boat to another crew member – the mate if you’ve already got a structure in place. This is imperative because once you get involved in the issue it becomes completely absorbing and someone needs to keep an eye on the big picture.

I have found it best to have a clear approach and be pedantic about working through it. One generally starts with a gut feeling of where the problem lies and this is the place to begin. If not I start with the batteries and work through to the main supply fuse. If this is fine I move on to the individual circuits. If you have a trip switch panel this will soon identify the issue.

Without a trip switch the voltmeter is your friend. There are so many variables from this point on I will leave you to head scratch your way through what will be a very individual problem. Navigation must be kept front and centre and if there isn’t anyone to carry this with their full attention, if you’re shorthanded offshore for example, set your alarm to go off every hour to maintain a consistent pattern of fixes.

I have spent over a day working on an electrical issue and it’s amazing how absorbing it can be. In the final analysis never forget that all you’ve lost is some of your aids to navigation. It is not a disaster; traditional skills will keep you just as safe and get you to your destination, but with a greater sense of satisfaction.

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