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With 22 lochs, the National Park is the perfect place to enjoy an invigorating and inspiring swim. Open water swimming in particular is a popular activity, and each year thousands of people take the plunge during mass participation events in Loch Lomond.


Open water swimming

Advice for open water swimming

Throughout the summer you will see groups of people donning wetsuits and bright coloured caps before taking to the water either to train for a competition or just for fun.

With more people than ever before braving the waters, there are clubs and smaller scale events to help you get started. Whether you’re a tentative beginner or an experienced open water swimmer, it’s essential that you’re well prepared before getting in the water. Before you head out read our guide on how to have fun and stay safe in the water.

  • Some places are better than others for swimming. Avoid busy boating/ferry areas where possible. Milarrochy Bay on East Loch Lomond is a popular site.
  • As you are low in the water, it can be difficult for other water users to spot you. So always wear a brightly coloured swim cap and, if possible, use a swim safety device – these are brightly coloured inflatable bags which you can tow behind you whilst swimming.
  • Swim with at least one other person.
  • Be aware of fishing lines in the water when close to shorelines
  • Where possible, use an escort canoe/kayak which can also display the alpha flag (international sign of diver in the water).
  • Always swim within your own capabilities and be aware of the effects of gradual chilling.
  • Check weather conditions before heading out, a large swell can quickly develop when wind directions change.
  • Blue green algae can be a problem during the warmer months. The relevant Local Authority should be the first port of call for advice if you spot any algal blooms, and SEPA can also be contacted.
  • When swimming in open water, there is a risk that you may develop a rash or itch known as Swimmer’s Itch (Cercarial Dermatitis). This is more common in the summer months and is an allergic reaction to a parasite most frequently found in shallow waters. Drying yourself with a towel on leaving the water can minimise the risk of developing symptoms. Symptoms usually clear up quickly but if they persist please seek medical advice. We would advise people experiencing issues to notify the local authority environmental health team.
  • In an emergency call 999, ask for Police and the rescue boat and provide the exact location of the emergency.

If you are planning to swim on Loch Lomond, National Park Rangers will be happy to answer any questions you might have. Contact the Duncan Mills Memorial Slipway in Balloch on 01389 722030.

Stop the spread

Invasive non-native species are one of the key threats to nature in the National Park. Aquatic plants and animals can sometimes be unwittingly transported into a new environment on people’s equipment such as wetsuits, kayaks and fishing gear. The introduction of new species can threaten the delicate ecosystems in the National Park.

Every time you leave any body of water (in or outside of the National Park), please follow the national ‘Check, Clean, Dry’ guidance:

  • Check your equipment and clothing for living organisms. Pay particular attention to damp or hard to inspect areas.
  • Clean and wash all equipment, footwear and clothes thoroughly. If you do come across any organisms, leave them at the water body where you found them or on a hard surface to die out.
  • Dry all equipment and clothing. Some species can live for many days in damp conditions.

Read the full Check, Clean and Dry guides for different water users.

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