A Beginner's Guide to Swimming Open Water in the UK

Where to Swim

There are well-managed open water lakes up and down the country that run organised sessions with appropriate safety provision in place, and this is where we would always recommend you start. Not only does it mean there are trained marshals, safety equipment and rescue protocols on hand, it also puts you alongside other like-minded swimmers.

This matters more than many beginners realise. Open water swimming is a remarkably social sport, and swimming in pairs or small groups is both safer and more enjoyable. Having someone beside you who understands what cold water feels like, who will notice if you're struggling, and who will share the post-swim warmth with you, makes an enormous difference, both practically and motivationally.

Acclimatisation: Respecting the Cold

The single biggest shock for most newcomers is the water temperature. Unlike the 28 to 29 degrees of an indoor leisure pool, UK lakes, rivers and coastal water are considerably colder, and cold water shock is a real and serious physiological response. Lincolnshire County Council and Lincolnshire Fire and Rescue have both highlighted that water temperatures in the county can trigger cold water shock even during heatwaves, and that this involuntary response, which causes gasping, rapid breathing and sudden loss of swimming ability, catches even confident swimmers completely off guard.

The good news is that your body adapts surprisingly quickly with regular, gradual exposure. Short, frequent dips will train your system to handle the cold far more effectively than occasional longer sessions. Each time you get in, you will find you last longer and feel more comfortable.

On entry, wet your face and the back of your neck before immersing yourself fully. These are particularly sensitive areas, and priming them reduces the initial shock significantly. As the water rises to shoulder level, try to exhale deliberately rather than gasping, as the ribcage contracts in cold water and this technique gives you a fighting chance of getting a controlled second breath, especially if the water is very cold.

Exiting the Water

Getting out safely is just as important as getting in. Your body temperature will have dropped, and the cold does not stop affecting you the moment you leave the water, a phenomenon sometimes called the afterdrop, where core temperature continues to fall for several minutes after exit.

The first priority is your head. Dry your swim hat and pull a warm woolly hat over the top immediately, as a significant proportion of body heat is lost through your head. Keep the swim hat on until you have properly warmed back up to your normal temperature. A changing robe, the kind that goes over your head and envelops your whole body, is one of the best investments you will make for post-swim recovery.

When getting changed, dry your feet and put your socks on first. Once fully dressed, a warm drink will help insulate your core from the inside out, though a word of caution: if you have been in particularly cold water, your perception of temperature is dramatically altered. What feels tepid to someone who has been standing on the bank will feel scalding to you. Warn whoever is making your drink.

Essential Equipment

• Wetsuit A good wetsuit provides thermal insulation and also improves buoyancy, both of which are genuinely safety-relevant in cold water. Try one on before buying, as fit is crucial. If it is too tight it will restrict your breathing; too loose and it will fill with cold water and drag. If you are training for a triathlon, wearing one is usually compulsory.
• Swim Hat A thick neoprene hat is the warmest option available and makes a meaningful difference to how long you can comfortably stay in the water. Silicone and latex hats are available and suitable for warmer conditions, but neoprene is the first choice for UK open water.
• Goggles Invest in a well-fitting pair that forms a reliable seal against your face. Open water sighting relies on clear vision, and poorly fitting goggles that leak or fog will undermine your confidence quickly.
• Ear Plugs These serve a dual purpose in open water, keeping cold water out of your ear canal and preventing your inner ear from chilling, which can cause disorientation and balance issues.
• Tow Float An inflatable tow float attaches around your waist and trails behind you in the water, making you visible to boats, other swimmers and safety marshals. It is a low-cost piece of kit that significantly increases your safety margin, particularly in busier waterways.
• Water Shoes Suitable footwear for approaching and leaving the water is easily overlooked but genuinely useful, particularly at lakes with rocky or uneven entries where a slip could cause injury before you have even started swimming.

Stroke Technique for Open Water

If you are coming to open water from pool swimming, you will already have a significant advantage, but open water swimming demands a slightly different set of skills. Efficiency matters far more than in a pool, particularly if you ever venture into coastal water where waves and chop will test your technique.

Bilateral breathing, meaning the ability to breathe comfortably on both sides, is well worth developing before you take on challenging open water. Waves, wind direction and other swimmers may make your usual breathing side impractical, and being restricted to one side in a race or rough conditions is a genuine disadvantage.

Sighting is the other key open water skill, and it is worth practising deliberately. The technique is to use a slightly deeper pull stroke to lift just your eyes above the water level, keeping the leading arm wide to support your hips and maintain your position while your fingers point downward beneath the surface. This minimises drag and allows you to glide as you sight, rather than losing momentum entirely.

When to Start

Open water swimming is one of those activities that genuinely changes people. The combination of natural surroundings, the physical challenge of the cold, the community around it and the clarity it brings to your mind makes it hard to give up once you have started properly. Start safe, start slow, and build from there. The water will reward you for it.