How Dangerous Is It To Swim Alone In Open Water? Must-Know Risks & Precautions

Human beings are not designed to breathe underwater; we do not have gills. Because of this simple and obvious fact, we do need to be aware of the dangers that come with swimming, either in a pool or in an open body of water. One common piece of advice is never to swim alone, but how dangerous is it really?

Swimming will always have inherent dangers, however the average number of people who die per year while open-water swimming in the UK is just 19. This is under 5% of the total number of drownings that happen in UK waters each year. This may be due to the fact that those people to partake in open-water swimming are more aware of the dangers that it holds. (Source)

Is Open-Water Swimming Safe To Do Alone?

Open-water swimming holds more potential hazards than a pool; currents, marine life, and boats, for example. Because of this, it is certainly advisable to swim with a buddy. The simple answer is that open water swimming is not safe to do alone, because no form of swimming is entirely safe to do alone. You could quite easily slip hit your head while getting into a swimming pool, and if there is nobody around then it could be very bad news.

What Are The Dangers Of Open-Water Swimming?

If you are looking to get into open-water swimming then congratulations, it is a wonderfully freeing experience.

However, be sure to know the dangers are so that you can avoid them in the first place.


Currents are like rivers of water within the ocean and some, such as riptides, can switch on and off at a momentโ€™s notice.

If you intend to swim in the ocean then ask locals about rips in the area, look for tell-tale signs such as waves not breaking in a certain area or the water looking more turbulent. Also know what to do if you get caught in a rip; never fight against it, instead swim perpendicular to the current until you are released and can make your way back to the beach.

If there are regular, long-shore currents in the area then try to swim against the current on your way out and back with the current so that you are not fighting against the current when you are already fatigued.

Marine life

Remove the image of Jaws from your mind; there were only 10 non-provoked fatalities globally from shark attacks in 2020 (source). That said, there are things to be aware of in the ocean. Be careful putting your feet down near rocks because sea urchins love clinging onto them. Look before you put your feet down so you donโ€™t get spiked.

Another possible issue is jellyfish, which can arrive in blooms on the currents during warmer months. Stings are rarely fatal but are often very painful. Knowing how to treat injuries from your local marine life is a must if you are starting open-water swimming.

Pre-existing health conditions

Issues that, under normal circumstances, would be dealt with easily can be much more serious in water. Conditions such as epilepsy, diabetes, asthma or heart problems are more easily dealt with on land than in the water, so if you know you have a health condition then take this into consideration.

Maybe stay closer to the coast, swim with a buddy or reconsider if open-water swimming is worth the risk. In these cases, it is always best to go and ask your local doctor to get some advice.

Cold & Aggressive weather

If your local waters are cold then be sure to take extra precautions. Wear a suitable wetsuit, and hood if need be. Have a blanket and a hot drink ready for after the swim so that you can warm up and always check the weather forecast before you go in case bad weather is moving in, in which case it would be wise to postpone the swim.

Rain and high waves make it difficult to spot people in the water if they get into trouble. It also makes for a rather miserable swim.  


Be aware of where boats are and are not allowed to operate and never swim in areas where there is boat traffic. As a swimmer you are very difficult to see, even with a colorful swim buoy you could be not be spotted and if you are hit by a boat then the outcome will never be good.

Even in an area where boats are not supposed to be, keep an ear out for any motors because not all people abide by the rules.

How Do You Stay Safe While Open-Water Swimming?

While we have said that swimming with a buddy is preferable, for some people this is not practical. Maybe you donโ€™t have a swimming buddy, or you cannot swim at the same times or the same speed. Whether you are swimming with a buddy, a team, or on your own there are certain precautions you can take to limit the risks. 

Be familiar with the area

If you are new to the area then definitely swim with someone else first and ask locals about potential hazards before entering the water.  

Have the right kit

If the water is cold then be sure you have a suitable wetsuit, if it is hot then make sure you have some waterproof sun-cream on. Some people also find that Vaseline around the neck and armpits can reduce chaffing.

Always have a swim buoy

These are not the same as life preservers, but they will allow you to lead on them to take a rest and, in an emergency, could make a massive difference. They have the added benefit of making you highly visible and some are even designed to hold your dry clothes and phone inside them.

Check out our recommended Swim Buoy in our list of Best Battle-tested Triathlon Gear

Let someone know where you are going

Always let someone on land know where you are going, your intended route, and how long you will be. This means that if you do get into difficulties then the emergency services have a much better idea of where to look for you in order to give assistance.

For more on this, check out How Far Can You Swim in The Ocean ? Must-Know Tips to Pick a Safe Spot & Timing!

Can You Get Sick From Open-Water Swimming?

Bodies of water such as rivers and lakes are not sterile environments. As such there is always a chance that bacteria or pathogens will be present in the water. Be especially careful around areas where cows graze close to the water because any rainwater entering the water is more likely to be contaminated.

Open water swimming can increase the risk of gastrointestinal infections (diarrhea and/or vomiting) as well as respiratory, skin, ear, and eye infections. Try not to swallow any water, take a shower as soon as you can after swimming and always wash your hands before eating in order to reduce any risks. (source)

Also check out our post on What You Need To Do After A Swimming Session? Wearables & Skin Care!

Why Do Strong Swimmers Drown?

Not many people can swim 10km in the open ocean. So if you are a strong swimmer who is training for a 10km race then it is less likely that you will have a buddy that can swim with you. At the same time you will be training longer and harder than most, and sometimes you can push too hard. If this happens when you are running then you can just collapse on the ground and have a rest, in the ocean this is not an option.

Being a strong swimmer in no way means that you cannot drown. Strong swimmers do drown, and the most likely reason for this is that they are more likely to push the limits of possibility.

Also, check our post Can You Forget How to Swim? What To Do & Are Kids Natural Swimmers!

Final Thoughts

Open-water swimming is a liberating activity. It offers a great combination of the solitude of swimming, with the vastness of nature that has us coming back time after time for another swim.

There are inherent dangers, as there are with any sport, but if we educate ourselves and those around us about these dangers then we can limit the risks and enjoy the freedom of open-water swimming.


An extreme triathlete who have competed in dozens of triathlons including IronMans and Extreme triathlons.

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