Open water swimming means swimming in seas, lakes and rivers rather than a pool. This guide covers what it involves, how it feels, and how to build from a first sea swim to the 33.3km distance.
Open water swimming is swimming in natural water such as the sea, a lake or a river, with no walls, lane ropes or black line to follow. Swimmers sight off landmarks, adapt to changing conditions and swim continuously. With warm water and full support, the 33.3km English Channel distance across four days becomes achievable for committed swimmers.
UltraSwim 33.3 is an Epic Adventure Swim Race™ covering 33.3km, the historic English Channel distance, split across five to seven point to point open water swims (we hate laps) over four days in warmer water locations (a half Channel 17km option exists). So far held in Croatia, Switzerland, Greece, Spain, Montenegro and the Caribbean, based at luxury spa hotels, with world class safety cover, premium support, a complete preparation programme and a diverse community that ranges from 14 to 74 years old, usually more women than men. From competitive Masters swimmers, triathletes and swimrunners to leisure and wild swimmers simply aiming to complete the distance. From a required pace of just 2km/h, any determined swimmer can do it. Come in a group or alone, everyone leaves with new friends for life. Award winning, all inclusive packages start from €1,575 CHECK (€750 for our 2 day Compact format)
Open water swimming takes place in natural water with no walls, lane ropes or black line to follow. You sight off landmarks, manage changing conditions, and swim continuously. It rewards steady pacing and calm breathing over sprint speed, which is why it suits endurance swimmers building towards multi day events.
In a pool you push off walls, follow a black line and swim in still, controlled water. Open water removes all three. You navigate by sighting, manage swell, current and temperature, and hold an even effort with no rest at the wall. These skills are learnable, and the reward is a form of swimming that connects you to real places and a global community of swimmers.
The iconic English Channel distance spread over 5 - 7 swims. Choose the full 33.3 CLASSIC, or the 33.3 / 2 BUILD 'Half Channel' which caps each swim at 5km. Life-changing for many.
Swiss precision event organisation. Boat and kayak safety cover provided on every swim. Daily briefings on conditions, route and pace. Experienced and dedicated team
Whether you come on your own or with a club, you will find your tribe, and make new lifelong bonds over 4 days of highs and lows as you reach for that 33.3 Finisher droplet
All iconic, each with their own challenges and beauty - Croatia, Switzerland, Greece, Montenegro, Spain and the Caribbean. From May to December and designed to fit your season and time constraints.
Explore the preparation programme, coaching and swim camps that get you to the start line ready.
Explore trainingMost swimmers start with short, supported sea swims and build distance gradually. With a structured plan, warm water conditions and full safety cover, the English Channel distance of 33.3km across four days becomes an achievable goal rather than a leap.
Watch swimmers describe their first open water experiences and how the group energy carried them through the toughest moments.
No. Open water swimming rewards steady pacing and calm breathing over speed. Most UltraSwim 33.3 swimmers are not racers; they are committed swimmers who build endurance gradually. The median age at events is 50, with swimmers from 14 to 74.
At UltraSwim 33.3 every swim is covered by boat and kayak safety crews, daily briefings and world class event management. You always swim within a supported group, so you can focus on the swimming.
UltraSwim 33.3 events are held in warm water locations, which removes the cold acclimatisation barrier that makes traditional Channel swimming so hard. Preparation can focus on endurance, technique and confidence instead.
Gradually, with a structured plan. Most swimmers start with short supported sea swims and build distance over months. The four day format breaks 33.3km into achievable daily swims, so the total distance is within reach of a committed swimmer.