There’s no getting away from the fact that tiredness profoundly affects our performance. Sleep deprivation can severely degrade our decision-making abilities. The latest scientific research into sleep, such as brain scans carried out by leading neuroscientist and sleep specialist Professor Matthew Walker, has shown how we are more likely to make flawed decisions when tired, sometimes with big consequences.

The military use sleep deprivation in training and selection procedures and have been at the forefront of research into its effects. Sleep education was considered an unusual subject when I first learnt to fly in the Fleet Air Arm, but there are many times sleep deprivation has been shown to be a major factor in accidents and disasters, from the Exxon Valdez tanker grounding and oil spill, to the Chernobyl nuclear disaster, and the fatal Air France crash in 2009.

On a less cataclysmic scale, two of Britain’s best single-handed racers have grounded their yachts while leading their race. They won’t thank me for mentioning it, but Mike Golding had a huge lead in the Around Alone Race in 1999 before he grounded on New Zealand’s North Island while suffering from heavy sleep deprivation.

Understanding your sleep cycle can help in making critical decisions

Meanwhile, in the last Route du Rhum, Alex Thomson had a 200-mile lead on the final approach to Guadeloupe. Unfortunately for Thomson, he slept through his sleep alarm and sailed Hugo Boss onto the rocks on the northern corner of the island and had to use his engine to extricate himself, incurring a penalty which lost him the race win.

Know your cycles

For sailors likely to experience sleep deprivation, understanding the different cycles of sleep is important, and can hopefully help mitigate mistakes. The cycles are categorised into Non- Rapid Eye Movement (NREM, both deep and light sleep) and the more active dreaming cycles of Rapid Eye Movement (REM).

During each cycle we experience a period of light NREM sleep followed by deep NREM sleep, followed by a period of lighter REM sleep – when we dream. Each cycle takes roughly 90 minutes. If we wake while in a NREM deep sleep phase we feel very groggy and take a while to properly wake up.

Article continues below…

How to plan watches and sleep when sailing short-handed

Before you decide on the best way to run watches double-handed, answer this question: are you sailing double-handed or single-handed…

Night sailing: top tips and expert advice to see you safely through until dawn

Sailing through the night brings its own rewards: a contemplative stillness, phosphorescent trails through a star-lit sea, the soul-warming sunrises.…

At night, we usually fall into deep NREM a few minutes after falling asleep. Among other benefits, NREM deep sleep helps your brain file away events of the day and clear the decks for lucid thinking once more.

Without deep sleep, our thinking often feels very ‘mushy’ and we can struggle with decisions the following day. Recent research into decision-making when very tired shows people often make over-optimistic gambles and can become reckless about losses. On the ocean this can negatively affect racing tactics or even key safety decisions.

Creativity has been linked with REM sleep. Most REM sleep is generally in the latter part of a normal night’s sleep, so only getting short naps for a prolonged period isn’t great for achieving the benefits of REM, but can provide some of the deep sleep of NREM.

Sleep on it

Ellen MacArthur famously enlisted the help of a neurologist, Dr Claudio Stampi, who trained her to sleep in a series of naps, like a baby. During the Vendée Globe her average period of sleep was just 36 minutes, and on one day she only achieved 1h 17min of sleep in total.

These days, most offshore racers would agree that short or ‘cluster naps’ are the best way to handle short-handed sailing. François Gabart slept in 20-minute bursts during his record-breaking solo around the world in 2018, once managing as much as six hours in a 24-hour period, other times much, much less.

As a race navigator, it makes sense to plan your sleep around key moments in the day, such as rounding a headland, receiving the latest weather or GRIB update, or when you plan to make a change of course. But you also need to be ready to react to unforeseen changes, or a rival’s course alteration.

The grogginess we experience between sleeping and being fully awake is known as sleep inertia

Before attempting to go to sleep it can be helpful if the navigator briefs the watch leader on tactical ‘what ifs’ so they might be able to sleep undisturbed – although I may be being optimistic here!

The old maxim of the power of ‘sleeping on a decision’ has also been backed up by neurological studies. Brain scans have shown that the brain mulls over problems while you are asleep. This unconscious processing can help lift the fog.

Dee Caffari experienced this during a solo transatlantic. She recalls: “During the Transat in 2008, the start was pretty full-on. All the boats were within sight of each other’s nav lights for the first few days. It was my first solo race in the boat and I had autopilot issues. I was tired and not managing myself well at all, as far as eating and sleeping.

“I was struggling to make a decision looking at the GRIB file that had come in. I could not make sense of it and make the critical decision of what angle to sail at. Eventually, I fed myself some pasta and slept for 30 minutes and it was like I woke as a different person.

“When I looked at the weather and routing, the answer came almost immediately. That was the first time I noticed the effect sleep deprivation had on life and death decisions.”

Critical decision making

• Prior preparation is essential – checking through the route, weather predictions, GRIB file update times and tidal stream changes.
• Use a waterproof notebook to make notes in clear, easy to read, bulleted points.
• Ensure you are well fed and try to have regular power naps. These are often best done on a reaching leg. I always have a secret stash of snacks for sleep-deprived navigators to raid.
• Brief your watch leaders thoroughly on what to expect and tactical ‘what ifs’, as well as when to wake you up.
• Anticipate and make sure you are wide awake for key points such as headlands, transition zones and when approaching land.

About the author

Mike Broughton is a pro race navigator who has won many titles including World and European championships. He is a qualified MCA Master to captain superyachts and previously had a successful career in the Fleet Air Arm flying Sea King and Lynx helicopters.

First published in the July 2020 edition of Yachting World.