Catching ZZZs

24 March 2009 By Kate Hubert

Whether you’re up at all hours serving drinks to guests and then back on duty for early coffee, or standing night watch on a long passage, getting enough sleep can be a real problem for crew. You often find yourself in a vicious circle of swilling caffeine to keep going, then desperately counting sheep when you do get some downtime.

So how do you get enough sleep, or learn to cope with less?

It may be that yacht crew can learn as thing or two from racing sailors. In the recent Vendée Globe single-handed race around the world, Australian racer Nick Moloney nearly died after going five days without sleep. Since then, he’s been working with sleep scientists to find out how to get by with as little sleep as possible, taken in short bursts.

If you’re not getting a full eight hours shut-eye every day, you’ll need to get scientific about your naps. To learn what works best for you, it’s important to understand a little bit about sleep cycles.

After you’ve been asleep for about 30 minutes, you go into deep, “slow wave” sleep. Your heart rate and breathing slows and you rest like this for 30- to 50-minute cycles, interspersed with five- to10-minute bursts of REM (Rapid Eye Movement) sleep. In REM, you’re not so deeply asleep and you move and dream more.

Slow wave sleep seems to be the most important type to make you feel really rested, and your body tends to cram more of this type of sleep into the first few hours of the night. That is why most watch systems have evolved into three- or four-hour cycles.

Another factor that really affects how you feel when awake is what stage of sleep you’re in when you get up. Left to wake up naturally, you’ll always awaken during REM sleep and feel alert quickly. But if your alarm wakes you during slow wave sleep, you’ll probably feel really groggy and won’t come round for a good half hour.

When you don’t have the luxury of being able to take even three to four hours off for a more restful sleep, you’ll need to take shorter naps. So what is the ideal length of time for a “power nap” to recharge your batteries and get on with your day? To avoid the groggy 30-minute recovery period, keep your naps to no more than 20 minutes each. Tests have proved that even a short catnap can increase your reaction times.

Lack of sleep can cause you to make mistakes – being overtired can make you as dangerous as a drunk driver – so take that nap.

But even if you do get some shut-eye during a busy charter season or ocean crossing, you still may not be getting all the rest you need. When Swedish scientists hooked a ship’s engineers up to EEM machines that monitor brainwaves, they found that if the engineers were on call, they would sleep more lightly, with much less “slow wave” sleep. Sound familiar?

The scientists also found that women tend to cope better without sleep – they take things slower and make fewer mistakes. Men tend to charge around in an effort to stay awake (which just makes them more tired) and try to do tasks as fast as if they had had plenty of sleep – but they make far more errors. So take it easy, guys!

The best advice if you’re sleep-deprived is the most simple – if you get the chance to get your head down, even for just 10 minutes, grab it – and tell the captain you’re not being lazy – you’re taking a scientific power-nap!