Open water swimming in London: supervised venues for triathletes

Open water swimming in London is possible all year at supervised venues. For triathletes, the main options are West Reservoir Centre in Hackney, the Hampstead Heath ponds, the Serpentine Lido in summer, Beckenham Place Park lake and, once its status is confirmed, London Royal Docks. Each sets its own rules on tow floats, caps and induction.

This guide sets out what each official venue page said when we checked it on 6 October 2026: where it is, who runs it, when it opens, what it asks of you and what it costs where a price is published. Rules and prices change, so confirm with the operator before you travel.

Why triathletes need open water practice

Pool swimming builds fitness, but a race swim feels different. You sight on buoys instead of following a line on the floor, you usually wear a wetsuit, the water is colder and other swimmers are close. A few supervised sessions before your first event let you practise all of this in calm conditions. If you are new to the sport, our triathlon for beginners guide explains where open water fits into a first season.

Supervised open water swimming venues in London

West Reservoir Centre, Hackney

West Reservoir Centre is on Green Lanes, N4 2HA, near Manor House station. Better runs it for Hackney Council. The venue says it is open all year round in any water temperature, with courses from 100 m to 300 m per loop that shrink as the water cools. A tow float is mandatory and provided, and you need a bright red, orange or pink hat. There is no induction, but you get a safety talk on your first visit. Booking is essential, in 1-hour slots, through Better. Adult prices run from £6.30 to £13.15 per session depending on membership (checked 6 October 2026). Full details are on our West Reservoir open water swimming page.

London Royal Docks (Love Open Water)

Love Open Water runs open water swimming at Royal Victoria Dock, E16 1AH, a few minutes' walk from Royal Victoria DLR. Loops range from 150 m to 750 m. When we checked, the venue page said "This venue is reopening in Summer 2026" and had not been updated, so its current status is not confirmed. Check the operator's page before you plan a session.

The page sets out clear requirements. You need NOWCA membership and a wristband, every swimmer must use a tow float, and a bright hat is required. A wetsuit is not compulsory, although the page notes that the RLSS recommends one below 15 °C. The benchmark is that you can swim 400 m unaided. A Cold Water Induction is compulsory from November to March and whenever the water is below 15 °C. Wetsuit hire costs £10 per session (checked 6 October 2026). You book through the ACTiO app after paying for NOWCA membership. Session prices are shown only inside the app, and the page does not state a minimum age.

Hampstead Heath ponds and Parliament Hill Lido

The City of London Corporation runs three natural bathing ponds on Hampstead Heath, in Camden: the Kenwood Ladies' Pond, the Highgate Men's Pond and the Hampstead Mixed Pond. It also runs the 60 m Parliament Hill Lido. The Lido and the Ladies' and Men's ponds open all year. The Mixed Pond opens from April to October. Summer hours start at 7 am.

Booking needs some attention. In summer, slots are released daily at 8 pm for seven days ahead, alongside drop-in entry. The booking system closed on 7 September 2026 and stays closed until spring 2027, so for now you pay or tap on arrival. From 1 October 2026 swimming is cashless only. Prices valid to 31 March 2027 are £5.00 for an adult pond swim (£3.00 concession), £5.00 for an adult at the Lido in winter and £8.80 for an adult summer morning or afternoon Lido session (checked 6 October 2026). Lido evening sessions are lane swimming for adults aged 18 and over. The pages we read did not state wetsuit rules or whether training groups are allowed, so ask the City of London before you plan structured sessions.

Serpentine Lido, Hyde Park

The Royal Parks run the Serpentine Lido in Hyde Park, W2 2UH. It is seasonal: weekends from mid-May, daily from June to mid-September, and closed for winter. Sessions run from 10:00 to 13:30 and from 14:30 to 18:00. Under-16s must be with a competent swimmer aged 18 or over. For the 2026 season, which ended in September, the page listed a full day at £8.40 for adults and £4.15 for children, and a single session £6.50 for adults and £2.40 for children (checked 6 October 2026). You can book online or walk up. For wetsuit advice and any swim test, check the Royal Parks page before you go.

Beckenham Place Park lake, south-east London

Outside East London, PTP Coaching runs open water swimming on the lake at Beckenham Place Park, a Lewisham park. From 1 October to 15 November 2026 the lake opens on Monday, Wednesday and Friday from 07:00 to 12:00 and on Saturday and Sunday from 08:00 to 13:00. Special swims are listed for 21 December, 25 December and 1 January. A one-off Cold Water Induction applies in colder periods, and winter swimmers must buy a Sports Guardian wristband at £19.95 (checked 6 October 2026). Children under 8 cannot swim, 8 to 14-year-olds take a competency test and swimmers aged 15 and over can book alone. Booking is through Sports Guardian. The swim price was not stated, so check PTP's page.

Open water venues compared

"Not stated" means the official page we read did not say. Opening patterns and prices change between seasons, so treat the table as a starting point and confirm on each operator's website.

Staying safe in open water

Swim only at supervised venues, during their sessions. Never swim in the Thames, canals or docks outside an organised session: you cannot see what is under the surface, boats may be moving and nobody is watching for you.

• Tow float. A tow float is a bright inflatable buoy on a waist leash. It makes you easy to see and gives you something to hold if you need a rest. West Reservoir and London Royal Docks require one. Our tow float guide explains how to choose and wear one.
• Bright cap. West Reservoir asks for a red, orange or pink hat and sells red caps at the centre. London Royal Docks requires a bright hat. Wear one wherever you swim so lifeguards can spot you.
• Cold water. London water cools quickly in autumn. Venues respond with inductions and shorter courses: a Cold Water Induction at Royal Docks from November to March and below 15 °C, a one-off induction at Beckenham in colder periods, and a smaller loop at West Reservoir. Get in slowly, keep your first swims short and get out if you start shivering hard.
• Induction and safety talks. Where a venue asks for an induction, waiver or first-visit briefing, complete it before you swim. It tells you where the exits, safety boats and lifeguards are.
• Swim within your level. London Royal Docks asks that you can swim 400 m unaided. If you cannot yet do that in a pool, build up there first.

What kit to bring

A short checklist covers most sessions:

• Swimsuit or tri suit, goggles and a bright cap.
• A tow float, unless the venue provides one (West Reservoir does).
• A wetsuit if you plan to race in one. See our triathlon wetsuit guide for fit and hire options.
• Warm layers, a hat and a hot drink for afterwards, plus a towel and something to stand on while you change.
• A bank card or phone for payment: Hampstead Heath is cashless from 1 October 2026, and the red caps at West Reservoir are sold by contactless payment.
• Your booking or app on your phone, and any membership or wristband the venue requires.

Frequently asked questions