The 9km Thames Marathon is a prestigious and demanding open-water swim that guides participants along a stunning stretch of the River Thames from Henley-on-Thames to Marlow.
This point-to-point endurance challenge is renowned for its scenic beauty and varied landscapes, making it a bucket-list event for seasoned swimmers looking to push their limits.
As swimmers journey through 9km of tranquil river waters, they are treated to views of lush countryside, charming villages, and historic bridges along the way. With exceptional event organization, safety support, and a friendly atmosphere, the Thames Marathon offers a rewarding experience for those ready to tackle a true long-distance challenge. Whether chasing a personal best or savoring the journey, this iconic swim promises an unforgettable adventure on one of the UK's most famous rivers.
Enter the race here.
Catch’s swimming courses give you everything you need to crush your goals.
.png){kind=small}
Swimming sessions will drop into your inbox every week, customised to your goals, lifestyle & ability.
Each week, a fresh video with a new aspect of front crawl will be available to watch, which'll match your weekly training plan.
Posted to your door, these cards will guide you through your sessions & drills.
Find local swim pals through Catch’s online community. The club content hub has heaps of technique tips, race recommendations, adventure ideas & more.
The Chillswim Coniston 5.25 Miles End to End is a premier open water swimming event held on Saturday, June 21, 2025, in the picturesque Lake District. Participants will swim the full length of Coniston Water, starting at the southern end and finishing at the northern tip near Monk Coniston Car Park.
Find out more
The Dock2Dock swim offers a unique opportunity to experience open water swimming in the heart of London’s Royal Docks. With towering historical cranes lining the water and the iconic skyline of Canary Wharf and the O2 Arena in the background, this event combines the thrill of urban swimming with the challenge of long-distance racing.
Find out more
The 4 Mile Henley Swim is a challenging open water race set in the River Thames at Temple Island Meadows during the Henley Swim Festival. This swim is perfect for those looking to test their endurance over a longer distance, offering a scenic and rewarding course along the historic river. With a mass start, participants will experience the thrill of open water racing in one of the UK’s most iconic swimming locations.
Find out more
The Dart10k is a challenging yet stunning open water swim, taking participants on a 10-kilometer journey along the River Dart in Devon. Starting in the historic town of Totnes, swimmers follow the river to the Greenway Estate, completing the swim surrounded by breathtaking natural beauty. Although the swim covers a long distance, the current in the River Dart is often a helpful force, working with you as you swim downstream, making it easier than swimming a standard 10k.
Find out more
Sign up to Catch Free
You’ll get access to the online swim community with training session ideas, mini courses, a swim content hub & local swim squad.
Get Free Access Now