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Register your place in 2022 Swim Serpentine!
Swimmers in action in the Children With Cancer UK Swim Serpentine on Saturday 18th September 2021.

Swimmer information

Key details about Swim Serpentine 2022

If you're taking part in Swim Serpentine on Saturday 17 September 2022, we’ll email you your Swim Day Guide a few weeks before the event. This go-to resource will contain everything you need to know about taking part in your chosen swim!

In the meantime, you can check out this page for more information about the route, disability support, swimmer safety, water temperature and age group prizes. 

Swimmers with disabilities

Our team supports participants with a range of disabilities at Swim Serpentine.

We've included a number of measures to help swimmers who require assistance to feel safe and confident at the event, including:

  • a ramped entrance into and exit out of the Serpentine
  • assistance with entering and exiting the water
  • accessible toilets and changing facilities

Please note that you do not need to enter a specific wave at the event to receive support.

If you have any further questions about the disability support available at the event, or if you need any additional assistance, please get in touch with us by emailing disability@londonmarathonevents.co.uk.

Swimmer safety

The Swim Serpentine course will be clearly marked by large buoys and a water safety team will be on hand to assist any swimmers on the day if needed.

All swimmers should be able to complete their chosen distance in full while training in a pool. Swimmers should also practise swimming in the open water before taking on the event.

There may also be Covid-19 safety measures in place at this year's Swim Serpentine – please check back here later for details.

General view of swimmers in action at the Children With Cancer UK Swim Serpentine on Saturday 18th September 2021.

Wetsuits and tow-floats

Everyone who takes part in Swim Serpentine must either wear a full-length wetsuit or use a tow-float for safety reasons. 

Wetsuits are optional at Swim Serpentine, but if you choose not to wear one you must use a tow-float instead.

Water temperature

The weather in the weeks leading up to the swim will determine the water temperature – so be prepared for anything here in the UK! For important information about water temperature and how it could affect your chosen swim, please look at the tables below.

Water temperature Course distance Wetsuits Max. time in water*
Half mile Optional
1 hr 10 mins


One mile Optional 1 hr 40 mins


Two mile Optional 2 hrs 50 mins


Super Six Optional 7 hrs**


Half mile Optional 1 hr


One mile Optional
1 hr 10 mins


Two mile Optional 1 hr 30 mins


Super Six Optional 6 hrs**

Water temperature and reduced distance guidelines

The maximum times in water detailed in the table below are only applicable when the water temperature is below 13.5°C. 

Water temperature Course distance Wetsuits Reduced distance
Max. time in water*
13.4°C and below
Half mile Optional
N/A 45 mins

13.4°C and below

One mile Optional One mile (800m option if swimming slower than 45 mins per mile pace) 45 mins

13.4°C and below

Two mile Optional One mile (800m option if swimming slower than 45 mins per mile pace) 45 mins

13.4°C and below

Super Six Optional Three miles (or 2 hrs 15 mins – whichever is reached first. This is 45 mins per mile pace, so swimmers must pass the second check-in in under 1 hr 30 mins**)

* Maximum times in water have been determined based on guidance from our medical and water safety team, in line with governing body guidelines and medical evidence around swimming in water of 14°C and below. These times will be used by our on-site safety team to monitor swimmers still in the water and assess the welfare of any swimmer exceeding the maximum time in water. Swimmers may be permitted to continue swimming beyond the maximum time in water providing they are assessed fit to do so by our safety team. Any swimmers showing signs of hypothermia will be asked to exit the water for their own safety and wellbeing. 

** Super Six swimmers will check in (while staying in the water) at the end of each lap. The water safety team will have the final say as to whether a swimmer can continue if they appear to be too cold or too tired, or if they are falling behind the maximum time limit.

Keep an eye on the Swim Serpentine Facebook page for the most up-to-date water temperature information in the build-up to the event.

Age group prizes

Swim Serpentine is not a competitive event – the focus is on taking part and having fun! However, we will be awarding age group prizes to the top three male and female finishers in the final two-mile wave of the day (classed as the ‘fast wave’, which swimmers must be able to complete in under 90 minutes, equivalent to a swimming pace of 45 minutes per mile) and the half-mile event for youths. The age groups are as follows:

  • Two-mile swim (final ‘fast wave’): 18-24, then all five-year age bands up to 75+
  • Half-mile swim: 12-14 and 15-17 age bands