Get into open water swimming

Regular wild swimmers will tell you it boosts their fitness, mood, circulation, immune system and even libido. So take a dive with us into the bracing world of open water swimming.

Open water swimming

Photo: Dan Bolt/

RNLI top safety tips:

  • Never swim alone. The safest way to wild swim is at an Open Water swimming site, with a club or between the red and yellow flags on a lifeguarded beach. If you can’t get to a lifeguarded beach, learn more about your chosen location and check hazard signage by finding an organised swim group in your local community.  
  • Acclimatise to cold water slowly and enter gradually to reduce the risk of cold water shock. 
  • Check weather and tide times before you go, avoid swimming in dangerous conditions.
  • Take a means for calling for help in a waterproof phone pouch and have this on you at all times.
  • If you see someone in trouble, call 999 or 112 and ask for the coastguard
  • Wear a brightly coloured hat plus a tow float for increased visibility.
  • Always swim parallel to the shore and not straight out. Cold water, waves and currents can tire you out quickly and make it harder to return to shore. 
  • Never swim under the influence of alcohol. 
Swimming in a pool

Photo: Shutterstock

How to enjoy the open water safely 

When you’re ready to try the open water, follow these tips from Nick Fecher, Water Safety Delivery Support at the RNLI: ‘It’s important to remember that things can go wrong in the water at any time of year. Average Irish and UK sea temperatures are just 12°C and rivers are colder - even in the summer. If you’re going in during the colder months or for extended periods, wear a wetsuit of appropriate thickness.

Gareth Morrison, Head of Water Safety at the RNLI, adds: ‘Always swim under close supervision, like a lifeguarded beach between the red and yellow flags – or at least with a group of regular sea swimmers. Tell someone on land where you're going and what you are doing. Always swim with a tow float, a bright swimming cap, suitable swim wear, your mobile phone in a waterproof pouch, and make sure you acclimatise to cold water slowly as this will reduce the risk of cold water shock. Always swim parallel to the shore and if you feel cold and start to shiver, get out of the water and warm yourself up’. 

If you’re at the coast and there’s an emergency, call 999 and ask for the coastguard. If you’re inland, call the relevant emergency service.

Exploring while swimming

Photo: Dan Bolt/

The RNLI’s top tips for taking a dip 

If you have access to a pool or access to a club in your area try these tips. Remember: You should never swim alone and we always recommend swimming under close supervision.

  1. Can you float? It might sound simple, but most people can’t do that picture-perfect version of floating. So we’re challenging you to go and find how you float effectively. Practise floating in a swimming pool as it’s a controlled environment. Then you’ll know what to do in an emergency in the open water.
  2. Try sighting. In the open water there are no lane lines, so practise swimming in a straight line. Lift your head to spot a landmark in the distance to keep you on track.
  3. Improve your technique. Lessons will really help with this. Put your head in the water to improve your body position. For front crawl, remember your leg kick – floppy ankles and long leg kicks from the hip. Practise more than one stroke so you can ease off when you need to. If you’re entering cold water, splash your face, wrists, ankles and back of your neck, to acclimatise to the cold.
  4. Find a club. Before you try open water swimming, find an organised group. You’ll need to learn about all the conditions that can change – tides, rip currents, winds and more. Plus they’ll tell you about any local hazards.
Catherine McMahon, Frosties swimmer

Photo: RNLI/Anna Burn

Catherine’s from the Frosties, a year-round swimming group in Skerries, on the north Dublin coast. She swims with her group at least twice a week without fail, all year round, even in the sleet and snow.

So why do wild swimmers do it?

Catherine originally got into open water swimming after an injury. ‘It’s great for the circulation. Cold water numbs everything and it’s invigorating,’ she enthuses.

It’s also a great way to stay fit throughout the year. Swimming just 30 minutes a week can also help to guard against heart disease, stroke and type 2 diabetes.

Swimming parallel to the shore

Photo: Dan Bolt/

It’s the mental benefits, not just the physical, that appeal to many open water swimmers.

‘It’s great stress busting. It has real benefits for people who are depressed. It’s my outlet – it keeps me mentally in shape,’ says Catherine.

Like all exercise, swimming releases endorphins in your brain, helping you to feel content and relaxed. Catherine says many in her group have high-pressure jobs. ‘Just half an hour swimming a few times a week has a calming effect,’ she says.

Can open water swimming stop you catching the common cold?

Many open water swimmers believe it boosts their immune system. So we asked our friends at the Extreme Environments Laboratory at the University of Portsmouth whether there was any truth to the common claim that icy cold swims fend off the common cold.

Professor Mike Tipton MBE and colleagues published a paper on this topic. Key conclusions highlight that the jury’s out: ‘There is some evidence that the short stress of CWI [cold water immersion] may prime the immune system to deal with a threat, and thus be beneficial … The definitive studies in this complex area await completion.’

Around the Mount Race for the RNLI

Photo: RNLI/Nathan Williams

Increasing popularity of wild swimming

There are dozens of clubs like the Frosties around our coasts and inland on lakes and rivers. There has been a surge in the popularity of open water swimming in recent years, helped by the rise of triathlons and marathon swimming. But for many groups, it’s not just about speed or long distances. 

As many as 80 people go out swimming each time with the Frosties, covering around a mile each time in about half an hour.

The Frosties welcome newcomers and triathletes to the group. Catherine says: ‘If we see someone new we advise them about local currents, rocks, jellyfish (in summer) and places to get out when they get tired.

‘Whatever your speed, I recommend you join a club - there’s a very big social element to it. It’ll give you a real boost.’

Open water swimming is very different to swimming in a pool. Even one of the safety-conscious Frosties group needed help from volunteers at Skerries RNLI recently.

To find out where you can get lessons or join an open water swimming club, go to the Swim England website.

Whether you’re swapping the swimming pool for open water or enjoying a quick dip, here’s how to stay safe

Get open water swimming tips