OSS Intermediate Tips for Safe Summer Swimming

Constantly changing conditions are part of the magic of outdoor swimming. Understanding water opens up safer, more adventurous swimming

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Whilst no activity is free from risk, and swimmers wouldn’t want their water free of the variables in nature – wind, tide, and constantly changing conditions are part of the magic of being outside – every summer there are tragic deaths and accidents in water which greater understanding may have preventing. To build on from OSS Top 10 Tips for Safe Summer Swimming, here are some more detailed tips on understanding risks, and staying safe. 


  1. SWIM SOBER: Alcohol and drugs impair your judgement, your swimming ability and your ability to regulate body temperature. Even small amounts of alcohol and drugs can have an affect, so avoid drinking or taking any drugs when swimming.
  2. FIND AN EXIT POINT: Check there’s a suitable exit point before you get into any water. In rivers, be particularly careful as currents are often faster than you think. Rip currents in the sea can reach 4-5mph, which is faster than an Olympic swimmer – learn how to spot a rip current before you get in.
  3. KNOW YOUR SWIM SPOT: Ask the locals about the best places to swim and read local hazard signs. The presence of a swim spot in a book, newspaper feature or website is no guarantee of its safety that day – conditions change, rain falls, rivers rise, currents quicken, temperatures fall, and the safety of all locations depends on the ability of the person in the water. Do your own risk assessment before getting in. Consider your experience and ability.
  4. KNOW YOUR LIMITS: aware of and honest about your own swimming fitness and ability outdoors. Swimming in open water is not the same as swimming in a pool, so stay within your limits.
  5. BE AWARE OF SUDDEN CHANGES IN DEPTH: Check the depth and what’s in the water before you get in. Don’t dive or jump in unless you know it’s deep enough and there are no obstructions. Conditions can change and tides can rise and fall rapidly, so water which was deep enough last time might not be this time.
  6. DON’T TRY TO RESCUE SOMEONE IN TROUBLE: Drowning people will drag you under. Raise the alarm at once. Dial 999 or 112 and ask for the Coastguard or relevant agency, to ensure trained professional rescue services are on their way. If you want to help, try shouting instructions about how to float, or find something buoyant you can throw to help keep them above the water. Do not enter the water without the correct training, experience or equipment.
  7. BE AWARE OF THE WEATHER: Rainfall can drastically alter the risk profile of a river swim. For example, high rains before your swim can bring faster currents, pollution, and change a river from one where it was possible to swim back upstream to a getting out point to one where you are swept along by the current. Lower rainfall before your swim can bring shallower water, which can make jumps which were previously safe dangerous as rocks are exposed. Lower rain can be linked to pollution too, as toxins are not diluted, whilst high rainfall can increase runoff from agricultural land and increase pollution in water bodies. Other weather can have an effect: swimmers can become engulfed in mist and sea fog. Wind can stir up chop, and increase chill. In coastal locations wind and weather conditions can cause bigger waves, stronger rip currents and bigger faster flowing tides.
  8. WATCH CHILDREN AT ALL TIMES: Find a safe area for children to play in and watch them all the time. It’s easy for them to fall in. Start them off with float aids even if they can swim in a pool, while they build confidence and experience natural temperature water. 
  9. AVOID FALLING IN: If you do, try to float calmly on your back for a 1-2 minute period, rather than swimming immediately. If you get swept downstream or in a rip current turn so that you are feet first on your back. Shout for help.
  10. AVOID SWIMMING CLOSE TO WEIRS: Many people swim in the pools upstream from them which is usually safe enough in low flows. The big danger area is at the bottom of the falls where circulating currents can trap swimmers and hold them under the water.


  1. BE AWARE OF COLD WATER SHOCK: Whilst  water warms with the air temperature and sun, the average sea temperature around the UK is 12 °c. Cold water shock can be triggered in water below 15 °c. Cold water has an effect on the body and can incapacitate the swimmer, weakening arms and legs. Increase your exposure to open water gradually, and swim along the banks (rather than across) lakes, for instance, so that you can exit the water when you feel cold. Larger bodies of water will be colder – see Understanding Thermoclines for more information, 
  2. BE HYPOTHERMIA AWARE: You can’t become truly hypothermic for at least 30 minutes and probably much longer in summer, however the cold water can cool your muscle tissue, which will affect your swimming and your coordination, so you might find it difficult to get out. Read the top questions asked about cold water swimming for key information about cold water, and understanding hypothermia so you know the signs. 
  3. GET IN SLOWLY: Jumping into water at less than 15 °c can cause cold water shock. One of the most common symptoms of this is an uncontrollable gasp. This can means water enters your lungs and you could drown. Following the gasp reflex, you might start to breathe very quickly or hyperventilate. This response isn’t under conscious control and lasts for one-two minutes. Get in slowly and ensure your breathing is under control before you start to swim.
  4. KNOW YOUR LIMITS: Reservoirs, lakes and rivers are tempting for swimmers to try to cross and it can be tempting to swim out to sea. Even strong swimmers can get into trouble because the cold weakens their arms and legs as the body tries to stay warm by diverting blood to the core. If this happens you can find yourself in trouble far from safety.


  1. SWIM AT LIFEGUARDED BEACHES: Where possible, stick to lifeguarded beaches when swimming in the sea, unless you are an experienced long distance swimmer. Obey the flags. If you get into trouble, signal for help by raising an arm or leg.
  2. BEWARE OF WAVES: Beware of waves if you can’t swim well. You can be knocked over and pulled out of your depth quickly. If this happens, float on your back, raise an arm or leg and shout for help.
  3. BEWARE OF RIVER MOUTHS: Be especially careful around locations where rivers meet the sea. There can be strong currents including rips.
  4. KNOW WHAT A RIP CURRENT LOOKS LIKE: Rips often appear safer to swim in as the water looks calmer. On many beaches, especially those with surf breaks, there may be rip currents that pull you out beyond the surf so avoid ‘rivers’ of calmer water within areas of waves. Rips also form along reefs pointing out to sea, piers, and groynes, so avoid these areas too. 


If you get caught in a rip, stay calm, they won’t drag you under. Don’t try to swim against it as you’ll get exhausted.

  • If you can stand, wade rather than swim.
  • If you can, swim parallel to the shore until free of the rip and then head for shore.
  • Always raise your arm or leg and call for help.



We all know the movie and TV version of drowning: shouting, waving, maybe screaming for help. This is not what happens in reality. People who are drowning:

  • Are usually silent: they are trying to gulp air and can’t shout.
  • Their mouth will bob above and below the surface of the water, and will be open as they try to gulp air.
  • Their head is often tilted back as they try to keep their mouth above water.
  • Their arms might be extended straight out sideways, and appear to be flapping as they try to push themselves up using the water surface.
  • They might appear to be doggy paddling or treading water, as though climbing an invisible ladder.


This drowning phase lasts for 20-60 SECONDS

What should you do:

  • Call for help – dial 112 or 999 and ask for the Coastguard when at coastal locations or 112 or 999 and ask for the Fire and Rescue service when at any inland waterside location. Don’t attempt to save a swimmer in difficulty  without the correct training, experience or equipment. They will grab you and try to climb up you, thus pulling you under.
  • If you want to help, try shouting instructions about how to float, or find something buoyant you can throw to help keep them above the water.
  • Learn Basic Life Support. You could save a life.
  • If you’re a strong swimmer, learn how to rescue someone, but only do this if the conditions are well within your ability and you are confident in your ability to rescue.

Further advice can be found on the RNLI website.



Like any outdoor activity, there are ways to swim safely, with respect for nature, your own limits and the surroundings . The OSS ethos is that people be free to swim, but carry the responsibility for doing so safely. Further information on how to assess and judge risk, and swim within your limits, is found throughout this survive section and in The Outdoor Swimmers’ Handbook (Kate Rew, Ebury). Please also see the Outdoor Swimmer’s Code to guide you how to minimise any negative impact on others and the environment as you swim.

The OSS Team