With a hot summer ahead, Brits will be packing bags, hopping on trains and heading to rivers, lakes and the coast in search of open water to cool off in. But first, it’s important to know how to do so safely.
When heatwaves and sunny days hit the UK, the scramble is on to secure a spot at a lido or outdoor pool. But in recent years, the pull of wild swimming has boomed, with many enthusiasts taking to rivers, lakes and the sea year-round — even during the winter months.
One of the key factors driving this growth is its numerous reported health benefits. A 2025 study linked regular outdoor swimming to improved wellbeing, finding that open water swimming (outside of a swimming pool environment) was associated with even higher wellbeing than outdoor swimming more generally. These findings support previous research suggesting that open water swimming reduces negative mood states such as tension, anger, fatigue, anxiety and symptoms of depression.
It can also ease aches and pains, boost your immune system and improve your circulation — it’s a relatively cheap and broadly accessible activity that requires little to no specialist equipment. However, it is not without risks. In 2024, there were 193 deaths in the UK from accidental drownings, across inland and coastal locations.
Why are Gen Z most at risk when wild water swimming?
An estimated 48.97 million people will visit the UK coast at least once over the summer, according to RNLI research released in May 2026.
The results from the RNLI survey that showed 44% of Gen Z respondents believed they were less likely to get into trouble in the water than their friends, while 37% said they would stand close to the edge of open water if it meant getting a good photo.
A further 26% said that following safety rules would spoil their enjoyment of open water, whilst 28% said they wouldn’t want to seem overly cautious around open water in front of their friends.
If you’re planning to swim in open water — particularly during hot weather, when the need to cool off can outweigh your usual caution — it’s important to consider a few safety precautions first.
How to prepare for a safe swim
“Before going swimming in open water, it’s important to be prepared. Check the weather conditions and tides — this might affect your plans,” says Gabbi Batchelor, water safety education manager at the Royal National Lifeboat Institution (RNLI).
She also warns: “Seek advice from a healthcare professional, especially if you have underlying health conditions and are going to experience cold-water immersion for the first time.”
What are the most common mistakes first time swimmers make?
One of the greatest risks of wild swimming is cold water shock, which can occur when swimmers enter water below 15C too quickly. Symptoms include involuntary gasping for breath, increased heart rate, increased blood pressure, uncontrollable breathing rates and panic.
“Acclimatise slowly to avoid cold water shock,” says Gabbi. “It’s important to enter the water slowly and allow time for your body to get used to the cold. Don’t jump or dive straight in, as this could cause cold water shock. Instead, splash your face and the back of your neck and try not to hold your breath.”
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How long is it safe to stay in cold water?
There’s no one answer to how long it’s safe to stay in the water while wild swimming, says longtime wild swimmer and founder of The Big Swim, Nicky Chisholm “It depends on water temperature, weather conditions, experience and acclimatisation.”
It also varies from person to person — someone who swims year-round will generally tolerate cold water for longer than a beginner.
For Nicky, the golden rule is awareness: “Leave the water feeling good, not depleted, which means leaving the water before you want to,” she says. “Always have warm clothes, a hot drink and a water bottle.”
When you get out of the water, warm up gradually, she adds: “Dry off quickly, remove wet clothing, layer up, put on a hat, drink something warm, eat a snack and avoid jumping into a very hot shower straight away.”
What to wear when wild swimming
You don’t always need to wear a wetsuit when wild swimming — most swimmers prefer standard swimwear unless the water is below 15C.
If you’re planning to participate in longer swims, Nicky advises purchasing a wetsuit, for warmth and buoyancy: “Try lots before buying and consider renting first. But the most important thing is to make sure you can move freely.”
Being visible in the water is always an important safety consideration. Gabbi also recommends open water swimmers wear a brightly coloured swim hat and consider using a brightly coloured tow float so that they have the best chance of always being seen.
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How to prepare for different types of water currents
Each environment presents different challenges, says Nicky. “Rivers have strong currents and hidden obstacles; lakes have cold water, limited exit points and difficult-to-judge depths; and the sea has tides, rip currents, waves and changing weather.”
If swimming in tidal waters, it’s important to look out for rip currents — strong currents running out to sea, which can quickly pull people out to deeper water. They’re difficult to spot but can be identified by a channel of churning, choppy water on the surface of the ocean. Beyond the sea, they can also be found around river mouths, estuaries and man-made structures like piers and groynes.
“If in doubt, don’t go out,” says Gabbi. “Before you enter the water, assess the conditions. If the water is too rough for swimming, don’t get in. Know your limits — depending on the conditions, you may need to swim less or closer to the bank or shore. The temperature of the air and water is also important … the colder it is, the less time you should spend in the water.”
She recommends downloading the RYA SafeTrx app (UK) or Irish Sailing SafeTrx app (Ireland), which can track your swim and alert emergency contacts if you fail to return home on time.
How to stay safe if you feel yourself panicking
If you find yourself caught in a rip current caught in a rip current or struggling in the water, the advice from the RNLI is to ‘Float to Live’.
- Tilt your head back with your ears submerged
- Relax and try to control your breathing
- Use your hands to help you stay afloat
- Don’t worry if your legs sink — everyone floats differently
- Spread your arms and legs to improve stability
“There’s no such thing as a safe swim, only safe swimmers,” say Kate Rew, founder of The Outdoor Swimming Society. “No water is safe if you can’t swim.”
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How to know if water is clean enough for swimming
Dangers of open water swimming also include pollution — from Weil’s disease to sewage releases, wild swimming isn’t without risk. According to data compiled by environmental charity Surfers Against Sewage (SAS), there were 584,001 discharges of raw sewage into UK waterways in 2023. Of the 86% of inland water bodies that fail to meet targets in England, 36% have been identified as failing directly as a result of sewage and wastewater discharges.
You can check for sewage alerts using the SAS Safe Seas & River Service, an app that provides a pollution forecast alongside surf conditions, wind direction, tide times, beach facilities and lifeguard services.
“We all want cleaner water and healthy ecosystems around it,” says Kate. “It’s natural as a swimmer to want to protect what you love. But swimmers don’t generally swallow water, so we’re more resilient to poor water quality than a lot of creatures we share the water with.”
Feature image: Pexels
