Unlike running, a swim marathon does not have a defined distance, but it is widely agreed that 10km is the minimum.

One of the most established, and beautiful, marathon swims in the UK is the Thames Marathon, a 14km downstream swim from Henley-on-Thames in Oxfordshire, to Marlow in Buckinghamshire. Last year the Thames Marathon was awarded the Best UK Swimming Event in the Racecheck awards, based on feedback ratings from the most important people – those that participated in the event.

This event is in its 9th year, and continues to grow in popularity, now attracting swimmers from all over the world. The event starts at the famous Leander Club in Henley, a prestigious backdrop for swimmers to prepare themselves for what’s to come. Once briefed, swimmers are set off in waves, with the fastest swimmers first. There are 3 stops en route, where everyone is required to get out of the water to walk around the locks. Here drinks and energy snacks are available to allow refuelling before re-entering the water to tackle the next stage. The locks are at 6km, 10km and 11.8km, nicely breaking up the swim into ‘do-able’ chunks.

Spectators can walk the entire distance from Henley to Marlow, the majority of the time alongside the river – there are a few pubs and cafes either on, or very close to the route, along with many other points of historical interest.

Thames Marathon

The finish is at Higginson Park Marlow, where there are plenty of options for food and drink and a chance to buy event memorabilia. Swimmers tend to hang around in the park for a while with their friends and family, to recover and watch the other swimmers finish.

Entries are already open for the 2019 Thames Marathon on Sunday 4th August. The majority of the swimmers must wear wetsuits, there are a small number of non-wetsuit places available to those that can demonstrate experience of swimming long distance without a wetsuit. These have all been allocated for 2019, and a waiting list is in operation.

Wetsuit places are available here. Register now to benefit from the Early Bird price – it won’t be around for ever.

Some Reviews from 2018

  • This is the must do event for any longer distance swimmers. From the initial entry through to the finish line everything is so smooth.
  • Enjoyed every minute of it … I think… 😉 Came over from Holland to do this event and not sorry for one second! Very well organised and lots of friendly and helpful volunteers! Thanks again to you all!!
  • This event is the absolute high spot of the summer. It is, in my opinion, the best event anywhere. The organisers and volunteers are passionate and helpful, the organisation is seamless and efficient, and the course… well, it is simply stunning. Make no mistake, this is a long swim, particularly when someone has turned the flow off, but, with three well-stocked feed stations, it is very doable. Give it a go. Your efforts will be rewarded.
  • My third consecutive year participating in this particular event. Although it is unique in the OW swimming calendar due to its distance, the time and effort that goes on behind the scenes at Henley Swim events is always obvious on the day. Registration was streamlined further this year and the option to register the day before is always welcome, bag drop, refreshments at the start line all great, clear concise explanation of the course, feed stations and on the water safety crews excellent. Plenty of well-informed staff at each stage and always a great vibe at the finish for competitors and supporters alike. Looking forward to next year, but with a bit of flow, hopefully!