Stay safe outdoors

Open water safety

Open water swimming refers to swimming in:

  • lakes
  • rivers
  • the sea

It has grown in popularity in recent years, and it can be good for your wellbeing.

Open water carries a number of biological, chemical or environment risks. Open water swimming can increase the risk of gastrointestinal illnesses and stomach bugs. Symptoms include:

  • diarrhoea
  • vomiting
  • respiratory, skin, ear and eye infections

Anyone can become unwell from swimming in open water. The risk of becoming ill depends on various factors:

  • Children and beginner swimmers are more likely to swallow water accidentally.
  • Those with a weaker immune system are more at risk of infection.
  • Those swimming in rivers and estuaries (a coastal body of water where a river or stream meets the sea) are more likely to become unwell.
  • Heavy rainfall can wash harmful bacteria from farmland, urban areas and sewage to rivers, seas and bathing waters. This can affect the water quality.

You should avoid consuming open water where possible.

You should wash yourself with clean water and soap after an outdoor swim, paying attention to your hands and any cuts or scrapes.

If you do become unwell with any of the above symptoms, seek medical help and let them know you have been open water swimming. Do not swim again until you have been symptom free for at least 48 hours. Your doctor may advise a longer period.

For more information and top tips on keeping safe, see GOV.UK: Swim healthy.

See water quality and Open Water Quality Position Statement for information on the water quality of our drinking and coastal waters. 

Our staying safe at the coast web page provides guidance around lifeguards and beach safety.