Guide to safe cold water swimming

UPDATE: September 2021: The water is getting slighter warmer every week in Melbourne and now is a great time to jump and have a go. The water is usually clearer and often calmer than summer months.

Here is the executive summary:

Cold water swimming is awesome. People start out hesitant and then love it. You will be in a good mood when you get out. Cold water swimming produces endorphins more effectively than just about any other activity, so you won’t regret doing it, safely.

Cold water swimming improves your mood

Yes you can swim for a short time in water temperatures from 10 to 15 degrees without a wetsuit but you will be cold and you will get colder when you get out. If you are not acclimatised to the cold water, you will probably need a wetsuit for temperatures below 15 degrees until your body gets used to the cold water. That takes weeks and months.

Walk in to the water slowly. Put your hands down in the water as you walk in. When your hands start to feel ok with the temperature (might take 5 to 10 minutes of standing around chatting), you are ready to dive in, though you might like to start with some breaststroke or water polo – head up freestyle.

The first ten minutes are confronting. Your face, hands and feet will feel the cold the most. After that you will realise that you’re starting to get used to it and you will even be starting to enjoy the amazing feeling all over. Like your whole body, nerves and and senses are being overloaded, bombarded, activated.

Bunch of newbies trying cold water swimming at Williamstown Beach, Melbourne.

Don’t stay in cold water (under about 15 degrees) for longer than 45 minutes until you are quite experienced. If you are too cold, you may not realise it so set a firm time limit for yourself and stick to it.

Don’t swim in cold water alone.

Always plan for your recovery after the swim. You will get colder when you get out. Have a thermos of hot tea handy and warm clothes. Get out of the wind and out of wet swimsuits.

Be prepared to move around in the sun or sit in a car with the heater on until you warm up again. Shivering is OK, it won’t last forever but you can’t drive until you warm up. So you need to schedule recovery time. For newbies to cold water swimming this might be up to 30 minutes.

Read below for more info about the cold water swimming including the risks and more about how to do it safely.

My personal cold water swimming journey:

Like most swimmers, I have come from a pool swimming background to open water swimming. I found the cold water a deterrent for a couple of years and would stop open water swimming in Autumn and come back to it in Spring.

I now swim in the ocean year round, often with no wetsuit in the middle of winter, down to temperatures of 9 – 10 degrees and love it, look forward to it and assist other swimmers to do it.

What I wear for cold water swimming:

I used to swim with a thick 5 mm wetsuit and thermal cap (see pic below near the end of this article). Now I wear two latex swim caps and ensure I pull them down over my ears to prevent the cold getting into my inner ears.

I’ve done away with the thick wetty and now wear a thin 2mm sleeveless wetty and that is more than enough for mid-winter swimming. So your body does change and adapt and you reap health benefits from doing it. You burn heaps of calories (but beware the urge to ‘carb-load’ afterwards).

No wetsuit winter swimming

UPDATE April 2021: Cold water swimming in Melbourne is starting again for winter 2021.

Check out this post for more information or go straight to this page to book in for supported cold water swim group, every Saturday at Williamstown Beach, Melbourne. This calendar list of open water swim groups and swim coaching in Williamstown, Melbourne has all our swim groups for open water and the pool and you can click straight through to book in, choose a date from the calendar and reserve your place for open water swimming or swim coaching.

Is cold water swimming good for you?

Is cold water swimming healthy? Is swimming in the cold winter ocean safe or advisable? What water temperature is considered cold in cold water swimming?

Firstly, yes, swimming in the sea during winter can be healthy and safe and completely energising and revitalising. There is no doubt that cold or cool water immersion can assist with blood circulation and science says this is just the start of the benefits. Your mood will improve and your brain functions will improve as a result of more blood flowing through the head.

But, and there is a big but, you need to know some of the basics before jumping in. And you probably won’t be jumping in anyway, more like a slow walk at best.

That’s because cold water swimming done wrong can be risky and dangerous to your long term health.

Is cold water dangerous?

Cold water swimming comes with risk. Here are the major ones:

  1. Cold water shock – When you first get in the water, you will feel the shock of the cold, especially on your head, hands and feet. The terms “Ice cream headache” and “Brainfreeze” will have new meaning for you. Your breathing will be constrained and you need to focus on your exhale to calm down. Cold water shock can lead to panic attacks requiring assistance or rescue. Enter water slowly with hands in the water. Don’t submerge your head in the cold water until you feel ready.
  2. Hypothermia – the big one. Hypothermia is when your body’s core temperature falls below 35C. This can lead to unconsciousness, organ damage, organ failure and cardiac arrest. You may not realise you have hypothermia or how low your temperature has fallen because your brain and body is not functioning efficiently. Never swim alone, never swim when you are shivering and never swim too long.
  3. Swim slow down – Cold water swimming causes your body to restrict blood flow to the arms and legs. This slows down your movements but you may not realise it. Eventually you can no longer swim properly. Don’t stay in the water if you are at all struggling or slowing down.
  4. Surfer’s Ear – Cold water can damage the inner ear. Pull your swim cap(s) down over your ears to prevent the water entering your ears or use ear plugs or even blue-tak in your ears.
  5. After-chill – When you get out, the cold blood in your arms and legs begins to circulate again, lowering the core body temperature. You may feel colder ten minutes after your swim than during your swim. Warm tea – to warm up your core from the inside and warm clothes as soon as possible is the best solution. A steaming hot shower straight from the cold sea is less effective and not very beneficial.

How to swim in winter / How to swim in cold water.

First – yes do it you will enjoy it. No one ever regretted a (safe) swim. Be prepared though if you want the benefits, not the injuries.

There is nothing enjoyable, smart, healthy or tough about swimming for long periods alone, far from shore in very cold winter water with just speedos to protect your modesty.

You can get hypothermia from swimming for long periods in relatively warm water – into the mid 20s degrees Celsius, so winter water needs to be respected.

First a wetsuit, gloves, boots, cap (or two) is the best way to protect yourself from the cold while swimming in winter. But even all this neoprene will not protect you from Hypothermia and all the associated risks after about an hour.

Second – Swim in a group, never alone, don’t stray far from shore and shorten your swim for winter.

Third: A thermos of hot tea is your best friend.

Fourth: A run along the sand before or after your swim can help keep you warmer or warm back up.

How long should I stay in the cold water?

Lifesaving Victoria say if you are in cold water for more than one hour, you almost certainly have hypothermia and are at risk of black out. Limit cold water swimming to less than one hour in winter when water temperatures are low.

If you have low body fat, you will want to be getting out of cold water after about 45 minutes, depending on the temperature.

What temperature is “Cold Water Swimming?”

Cold Water swimming is a general term but there are guidelines and health and safety regulations around cold water swimming events. Swimming Australia, FINA, triathlon organisations all have rules for cold water swimming based on health advice. All too often these rules get developed after a tragedy or many, so let’s find out more:

Cold water swimming temperatures in centigrade/Celsius:

Mid 20s degrees: warm enough for everyone

22C: Warm in Victoria, but a bit nippy for northerners from NSW and Queensland!

20C: You might like a wetsuit for long swims.

18C: Time for a wetsuit. FINA and Swimming Australia say wetsuits (not swim suits) are mandatory in OWS events under 18 degrees.

16C: FINA and Swimming Australia rules say no event can be held in water under 16 degrees.

15.5C: Swimmers who want to qualify for an English Channel attempt must swim for two hours, without wetsuit in water that is 15.5C or less. This is really cold and you will need time to recover from swimming in water of this temperature. You can’t leave the water and expect to be able to drive a car, for example.

10C: This is cold. Limit swims to well under one hour and do not attempt without a wetsuit at very least.

8C: Do not enter the water for more than a very short period of time – max 30 minutes – for the most experienced swimmers.

5C: This is called Ice swimming. Please seek medical advice.

I no longer need or want the thermal cap and thick wetsuit. My body has got used to the cold water and I look forward to winter swimming, when the water is crisp and clear and invigorating.

This POV swim video will make you feel like you’re swimming. Put it on big screen

One thought on “Guide to safe cold water swimming

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s