Brrrrr it’s COLD in There! Pass the TEA.

Winter Swimming in the English Channel

Here off the south coast of the UK in the English Channel the water never reaches temperatures above 20 degrees. Even at 20 degrees the water is chilly but as we say goodbye to summer and head into autumn and winter the water temperature in the channel will dip as low as 5 degrees.

The most important part of cold water swimming is of course the SAFETY. The sea can be an unforgiving place and knowledge is power so what do we need to know?

Knowledge of the Sea

It is so important to know what is happening in the water, don’t rely on others to tell you, you should know for yourself.

Check out the forecast for your local swim spot, what are the tides doing, flooding in or ebbing out? What does that mean in relation to the direction of current? In our area as the tide floods in the current pushes east up the channel. The tide turns back on itself quite early here usually about 1-2 hours before high or low water depending on the spring or neap tides. If you are not sure seek advice from a qualified coach in your area.

Wind causes waves. The speed, fetch and direction all play a contributing factor as to what kind of sea you will be greeted with. Wind speeds of 15 mph or more directly onshore will create a sea that will not be comfortable for most to swim. Study the figures and look at the sea, you should start to figure out what to expect. It may be that you can tell from looking at the forecast before you even leave home, that today is not the day for you. If the forecast looks promising, great, but don’t be pressured into going in if looks too much for your experience.

How cold and how long?

The water temperature affects people differently. Watching the old lady walk down the beach in her swimsuit and towel and head bravely into the 6-degree water is most definitely inspiring but if you are not acclimatized to that temperature, it will for sure be more painful and possibly dangerous without essential knowledge.

The amount of time in the water is dependent on you, one size does not fit all. Your physiological state on that particular day has a large determining factor on how quickly you feel cold. Have you been poorly, slept badly, mensurating, dehydrated, hungry etc. There is a saying floating around in the open water swimming world that 1 minute per degree of water temperature is the guide as to how long you can stay in, back to the one size fits all statement so ideally we want to listen to our bodies and not clock watch.

My advice is to get out before you start to shiver. Shivering is good as its out bodies way of producing heat but ideally we want to be rewarming at the same time. If you were to start shivering in the cold water and then started to feel all warm and fuzzy you are probably going into hypothermia.

Take it slow, wear exposure protection and don’t think you are Wim Hof just yet.

Acclimatising V’s Acclimatising

There are 2 kinds of Acclimatising,

  1. Training our bodies over time to adapt to the cold water. Frequent, regular exposure over a period of several months will show an adaptation to cold water. This exposure also has shown a 50% reduction in the cold-water shock response. Once you have acclimatised to the cold water cold water swimming will be a breeze.
  2. Gradually getting in the water so we do not experience cold water shock. The best way is slowly, splash some water over the body whilst in the shallows, move in a little deeper, slowly letting each part of the body feel the cold. Flood water down the wetsuit, go out and and come back in if the sensation takes your breath away. Breath slowly in through the nose with an extended outbreath to calm the body.

Cold Water Shock causes the blood vessels in the skin to close, which increases the resistance of blood flow. Heart rate is also increased. As a result, the heart has to work harder, and your blood pressure goes up. Cold water shock can therefore cause heart attacks, even in the relatively young and healthy. The sudden cooling of the skin by cold water also causes an involuntary gasp for breath. Breathing rates can change uncontrollably, sometimes increasing as much as tenfold. All these responses contribute to a feeling of panic, increasing the chance of inhaling water directly into the lungs. This can all happen very quickly: it only takes half a pint of sea water to enter the lungs for a fully grown man to start drowning. You could die if you don’t get medical care immediately. Taken from the RNLI 

Exposure Protection

Exposure protection is a personal choice. If you don’t know yet i would start in a wetsuit and then progress to what we call skins swimming (with only your swimsuit) if that is your goal, both options have their pros and cons.

Swimming in a wetsuit makes you more buoyant which can be a plus if you are a bit nervous, if it is too buoyant though it will be tricky to swim in so do some research or contact me for some advice on the best kind. A wetsuit will allow you to have a longer swim as you will not feel the cold as quickly. Be aware though you will still get the initial cold-water shock as the water floods into your suit to fill in the gaps. Wetsuits also offer a layer between you and things in the water 😉

Swim socks or boots and gloves are a real game changer for winter swimming as numb hands and feet make getting out and changing hard work. Neoprene swim hats do a great job in keeping the heat in or a couple of silicone hats do a good job too. Woolly hats are an idea but if they get fully wet, they are useless and heavy.


This phase is a real deal breaker in coping with winter swimming. It is unlikely with short dips in water of between 5-10 degrees that you will become hypothermic but not being able to rewarm and feeling cold all day is not the most enjoyable thing in the world.

There is a common condition associated with a continual cooling of the body after exiting the cold water, this is called the AFTER DROP. The body will continue to cool despite being re-warmed for between 10-40 minutes post swim. This is when many start to feel a real dip in body temperature.

The key to warming up and staying well is to warm up slowly and gradually but effectively and promptly.

  • To minimise the risk of afterdrop, dress immediately starting with the top half of your body.
  • Shivering is a good sign that your body is working to re-warm itself
  • Dry yourself off ASAP – remove all wet layers and pat yourself dry.
  • Layer up: in thermals, wool jumpers, insulated jackets, woolly hat and gloves, long coats.
  • Stand on something as you change to avoid losing more heat from your feet.
  • Sip a warm sugary drink, the hot drink won’t do anything other than an instant treat but the sugar will help.
  • Eat something sweet, the sugar will help raise body temperature.
  • Sit in a warm place, a gentle heater on in the car can help but not too hot.
  • If you feel okay, walk around to generate body heat. It can take some time to warm properly.
  • Hot baths and showers can be tricky, they trick the peripheral layers of the body into thinking it is warm when the core is still cold. They may also affect blood pressure and make you feel faint and unwell. Professor Mike Tipton says a key is to have them warm, but not hot.

Staying Safe

  • Swimming with others has it benefits, not just from a social point of view but most definitely from a safety aspect. Having buddies with you in the water or on the shore to raise the alarm if needed, can be lifesaving.
  • Take your mobile with you in a dry bag so you can call for help yourself. Remember to call 999 and ask for the coastguard.
  • Be able to float.
  • Wear a safety float/ swimming buoy/ tow float.
  • Be visible in a brightly coloured hat.

Dee Harmer is a qualified STA Open Water Swimming Coach, Swim England Level 2 Swimming Teacher, Surf Life Saving Great Britain Level 2 Lead Coach and Surf Lifeguard. Dee is also a Scuba Diving Instructor, HSE Commercial Diver & holds Level 2 RYA Powerboat Qualification.