Polyphasic sleep management: solo, double-handed and crewed

Sonno-polifasico

Polyphasic sleep management when sailing single-handed is one of those aspects that terrorises each and every sailor who has not yet sailed by themselves. It is not a simple subject to deal with and requires plenty of practice. It is only with time that we learn how to manage polyphasic sleep both single-handed and short-handed. Obviously the two are quite different. However, the basic principles that are at the basis of the single-hander’s sleep management, are useful in determining watches when sailing double-handed.

Polyphasic sleep management – fundamental principles

In order to understand the difficulties in managing sleep we have to take a step back. When we are born we sleep and wake regularly to breastfeed. Our body isn’t in fact programmed to stay awake for the whole day and sleep during the whole night. It is between birth and the age of 4-5 that we learn how to sleep like an adult, but we do so going against nature.

Sonno polifasico di un roditore
Polyphasic sleep in a rodent

Observing the behaviour of a newborn growing tells us lots on what are the natural cycles of polyphasic sleep. In ancient time humans were already used to sleeping at night and hunting and gathering during the day. However if we think of our ancestors living in caves their sleep was probably a series of naps. It was important to be able to react quickly in case of an attack from predators.

If we go even further back, we didn’t even have the protection of fire. Before we learnt how to control this element, humans certainly couldn’t afford to take a long night-long sleep. In fact it has been demonstrated that our DNA is not wire for such behaviour. The management of polyphasic sleep for our ancestors was a matter of survival. The management of polyphasic sleep in modern times is on the other hand totally related to social organisation. Homo Sapiens’s sleep management is the only exception in the animal world, among mammals, having changed from polyphasic to monofasic (only one sleep phase at night, rather than several sleep phases during a 24 hours period).

Nessun mammifero dorme tutta la notte, solo alcuni uccelli
No mammal sleeps an entire night, only some species of birds do.

How a newborn can disrupt our routine

When we observe a newborn and we think of humans before the discovery and control of fire, we notice how polyphasic sleep and alertness are totally unrelated to day-night cycles. A newborn does not sleep more or less during day or night, this creates a lot of disruption in the habits of a parent otherwise used to monophasic sleep. It is the mother, often, to pay the worst consequences, especially if breastfeeding and having to wake up repeatedly whilst not being used to it.

Sonno polifasico: come cambia il sonno dei bambini crescendo
Polyphasic sleep: how sleep patterns change as children grow up

Sleep cycles in a newborn just match their stages of sleep and wake, nothing more. The duration of each phase of sleep during their polyphasic sleep initially does not goes past two hours. Growing up however the newborn will start skipping some of their moments of wake at night, giving us a full 3-4 hours of sleep. This change slowly brings about sleep that is defined as semi-monophasic. During the day the newborn may by contrary skip one of the naps and stay awake a little longer. Progressively a child may only wake up once a night, but still need an afternoon nap.

It is towards 3-4 years of age that the afternoon nap is often lost. Children of this age start to concentrate all their sleep during a single phase during the night. The exact age can vary considerable from child to child. After 4 years of age our little ones are the best of sleepers and can easily clock 11-13 consecutive hours of night sleep without ever waking up. It is important to understand that it is the child that has adapted to the surrounding world, to parents sleeping at night. Ancestral instinct would have the child carry on sleeping in naps in a polyphasic sleep pattern.

Sleep management: monophasic and polyphasic

A baby that alternates sleep and wake during the whole day follows a pure polyphasic sleep pattern. “Poly” simply means multiple, a sleep in many phases. At the beginning, much to the desperation of the mother, the polyphasic sleep pattern is perfect. That is, the child not only will naturally wake at night but may stay awake and play at night before falling asleep again. Many parents know full well how disruptive this is and yet how normal and natural it is too.

Progressively polyphasic sleep becomes purely monophasic. It will all start with the child finnally skipping some awake time at night and sleeping fewer naps during the day. When night time sleep becomes predominant we speak of semi-monophasic sleep.

Sonno polifasico e monofasico
Polyphasic and Monophasic sleep

As a toddler grows up goes through many changes, walking and talking as well as adapting to monophasic sleep. Eventually the child may stop altogether even the habit of an afternoon nap, in this case it is important to ensure they are still getting enough overall sleep hours, and it is important to fully understand where that nap came from in the evolution of their sleep pattern.

Day-night cycles

You would probably think that a person under experimental condition would follow some sort of cycle linked to the 24 hours duration of a day on earth. In fact it has been demonstrated that our natural cycle under controlled conditions is of approximately 25 hours. This is defined the primary circadian cycle. I leave it to the curious to find out more about this aspect which is somewhat less important to our needs. It was studied by Claudio Stampi during his participation in the Whitbread and during Ellen MacArthur‘s round the world record attempts. In absence of external factors humans would tend to increase their sleep-wake cycle to up to 36 hours, however we are digressing here.

Ciclo cicardiano primario (25h)
Primary circadian cycle 25h

Then, there is a secondary cycle within the primary circadian cycle defined simply secondary circadian cycle. Our feeling of tiredness or alertness is typically associated with specific time of the day. Every helmsman that has been at the wheel in a deserted cockpit just before sunrise knows well how difficult those hours can be. This is because our body is fighting against the natural circadian cycle that brings a heavy desire to sleep. Another such example is of the circadian cycle is the desire to nap in the afternoon still part of normal culture, the siesta. This tradition is almost universally lost due to the organisational needs of modern society, but it’s function was very clear and dictated by circadian cycles.

 Minore efficienza nel primo pomeriggio

Lesser efficiency in early afternoon

In its natural cycle, 12 hours after the low point which occurs at night, our body experiences a secondary low point in the afternoon. It is important to note that this has nothing to do with daylight. The ability and possibility to sleep when our circadian cycle demands it would be fantastic. Unfortunately it is not compatible with modern life which requires we are awake all day. However when we get older and we get out of the normal working hours patterns and purely monophasic sleep pattern slowly breaks apart and progressively we return to a semi-monophasic or purely polyphasic sleep which is normal in old age.

Il passaggio dal sonno monofasico a quello polifasico
The passage from monophasic to poliphasic sleep

The single sleep cycle within polyphasic sleep

Not all sleep is the same, this is a cardinal principle to understand sleep management for the sailor. When we go below deck, we dont fall asleep instantly, we go through an adaptation phase. The moment we fall asleep, our sleep becomes progressively deeper. We take approximately 20 to 25 minutes to enter deep sleep which peaks at around 40 to 50 minutes after falling asleep.

Sonno polifasico - turno di riposo - Global Ocean Race - Sergio Frattaruolo
Polyphasic sleep – rest time – Global Ocean Race – Sergio Frattaruolo

After reaching the peak of deep sleep, we return progressively towards a state of wake. During the night we think we are sleeping uninterruptedly all night long, in fact we sleep a series of cycles. From deep sleep, after another 45-50 minutes, from a cerebral activity point of view, we are awake. This is the REM (Rapid Eye Movement) phase during which we dream. If we were to be woken up at this moment we would feel quite fresh and ready to go. So a whole sleep cycle lasts approximately 1h 20′ to 1h 40′. This is the total time from falling asleep to reaching the first REM phase which occurs after deep sleep. To become an expert in managing polyphasic sleep, you must learn how long is your typical full cycle.

When conditions allow, single handed, short-handed or fully crewed, we should try to sleep one or more cycles during the day. The time spent in our bunk should be a multiple of the each cycle and must include the time to get comfortable and fall asleep. If we include the time spent going below and taking our foulies off we should aim at a minimum 2 hours for any given attempt at sleep. When sleeping a full cycle is possible we should sleep at least one cycle at a time, wake up, do our routine checks then sleep again. There are conditions when however we cannot sleep a full cycle and we will look at how we can substitute polyphasic mono-cycle sleeping with napping.

Short-handed sailing sleep management

By short-handed we refer to the typical double handed race. There are various strategies to manage watches. A lot depends on how two co-skippers get on well and their level of preparation in respect to polyphasic sleep management. My piece of advice is that the less you know each other the more the rules must be strict. Two co-skippers that have sailed many miles together on the other hand can use much looser watch systems.

To give some practical examples, when I sailed with Paul Peggs, we didn’t have fixed watches. We had already sailed together at the Round Britain and Ireland as well as many other training miles. It was also quite evident that I had a propensity for being awake at night. On the other hand Paul didn’t like nights, especially as he likes spending a lot of time at the helm. On the other hand I dedicated a lot more time to the study of the weather and the optimal route. Therefore, during my watches I used mainly the autopilot and helmed only for pleasure or need. This ultimately led to me during more night watches on average.

Paul Peggs alla barra - Global Ocean Race 2011/2012
Paul Peggs at the helm – Global Ocean Race 2011/2012

This flexibility also meant that each would quite freely declare when we were tired and could sleep accordingly. Going to sleep when you feel tired is much more efficient than having to stick to a given schedule so that ultimately you need less sleep. The natural alternation still meant there were times when we were both awake and those were the times to discuss the strategy for the following hours. When one was asleep we tried to wake the sleeper only if strictly required for manoeuvres in tricky conditions or when in turn feeling tired.

Don’t miss the sleep train

Managing sleep freely like Paul and I did is a luxury. It solved many problems but laid its foundations on the total reciprocal trust. I tended to cover most of the night but Paul worked hard at the helm during the day and we knew that we could ask for a watch change at any point in time. This approach however requires that both are used to single-handed sailing, carrying out most manoeuvres solo, and a good knowledge own needs.