Compiled and fact-checked by Tommo, Verus founder · Last verified August 2026 · Spot an error?
Dorney Lake Guide
Dorney Lake triathlon and open water swim guide: who runs events there, the 2012 Olympic rowing course, wetsuit rules, transport and parking — plus every organizer currently racing at the venue.
Venue At A Glance
Dorney, Windsor, Berkshire, UK
SL4 6FJ
Triathlon, Duathlon, Open Water Swim, Aquathlon, Aquabike
6 running events here
Dorney Lake is Eton College's purpose-built rowing venue, constructed 1996-2006 and used as the rowing and canoe sprint course for the London 2012 Olympics. It isn't a single-race venue — it's a shared course that multiple independent event organizers book throughout the year for triathlons, duathlons, open water swims and aquathlons, alongside its day-to-day life as a rowing lake. That means there's no one 'Dorney Lake triathlon' — instead there's a rotating calendar of events, each run by a different company, all using the same stretch of water.
Who Runs Events Here
There's no single published figure for total events per year across every organizer. Adding up what each one lists separately, a realistic estimate is 15-25+ event dates a year at Dorney Lake — but treat that as an approximation, not a sourced total, since nobody publishes one combined calendar.
RunThrough Events / ATW Events (Dorney Lake Events)
Triathlon, duathlon, and standalone 5K/10K/half marathon runs
The dominant year-round series — roughly monthly, February to December
Visit organizer siteActive Training World (ATW)
British Triathlon-sanctioned draft-legal triathlon (2026 Sprint World Championships qualifier)
Annual
Votwo Events & Adventure
Eton Dorney Triathlon, plus "Swim Long Eton Dorney" (2.5K/3.8K/5K/10K open water swim)
Typically one weekend a year, usually September
F3 Events
Dorney Lake Triathlon, Evening Triathlon, Weekender Triathlon, and standalone swim events
Several dates across the season
OneRace Events
"The One on the Lake" and "The One for the Planet" — triathlon, aquabike, duathlon, aquathlon and swim formats
Multiple dates across the year
The Race Organiser (AAT Events)
Winter/Spring duathlons and standalone lake runs
Several seasonal editions
Dorney Lake's own site (dorneylake.co.uk) is the real official source for the venue itself, but its FAQ is explicit that the venue "will not be able to answer any queries about your event" — it doesn't run a unified calendar of the triathlons, swims and duathlons hosted there. For a specific event date, go to that event's own organizer (listed above), not the venue site.
The Course & Wetsuit Rules
The lake is a 2,200m, eight-lane regatta course (each lane 13.5m wide) plus a separate return lane, giving a flat, straight, still-water swim with none of the current or chop of a river or sea venue. Depth and exact buoy layout vary by organizer and event distance.
Facilities
- The Boathouse is the event hub: changing rooms, toilets (including accessible), and a large viewing balcony overlooking the lake.
- Catering runs during events only — there is no permanent on-site cafe, though a coffee van operates on non-event days.
- Portable toilets are added trackside on race days.
- Transition sits directly in front of the shower/toilet block, with the swim exit feeding straight into it.
- Spectators are permitted throughout the start/finish area and the boathouse balcony.
Getting There & Spectating
Transport & Parking
By car: M4 Junction 7, then Lake End Road/Court Lane. Satnavs sometimes misdirect to Dorney Court instead — a separate, nearby address that shares part of the postcode — so double-check you're heading for the lake, not the historic house.
Nearest station is Taplow on the Elizabeth Line, then a short taxi (sources vary on distance — allow 10-15 minutes).
The official venue site describes complimentary on-site visitor parking, while third-party parking-aggregator listings cite a £2.50 all-day pay & display charge. This discrepancy likely reflects general grounds visiting versus event days — check your specific event's own information for what applies on race day, since organizers may set their own arrangement.
Spectator Guide
The Boathouse balcony gives a clear view over the start/finish and transition area, and spectators can move freely around the venue's perimeter to watch different points of a lap course. Exact viewing guidance (e.g. any restricted areas) is set by each event's own organizer rather than the venue.
what3words: ///entire.vibes.sport
Frequently Asked Questions
Is Dorney Lake connected to Ironman or T100 triathlon?
No. T100 London is held at ExCeL and Royal Victoria Dock in East London, not at Dorney Lake. No Ironman or T100-branded race has been held at Dorney Lake — every event there is run by an independent organizer (see the list above).
How do I find out what events are on at Dorney Lake?
There's no single combined calendar. Check each organizer's own site directly — RunThrough/ATW's dorneytriathlon.com covers the largest, most frequent series, with Votwo, F3, OneRace and The Race Organiser each publishing their own separate dates.
Do I need a wetsuit at Dorney Lake?
It depends on water temperature on the day, checked roughly an hour before your event: compulsory below 14°C, optional 14-22°C, banned above 22°C. This is the standard British Triathlon rule, applied by whichever organizer is running your event.
Is parking at Dorney Lake free?
The venue's own site describes complimentary on-site parking for visitors, but some third-party parking listings cite a £2.50 all-day charge — likely a difference between general visiting and event days. Check your event's own race information for what applies on the day.
Can I go open water swimming at Dorney Lake any time?
No — the official venue FAQ states open water swimming is "not offered" for casual/public use and suggests Bray Lake as an alternative. Organized open water swim events (run by Votwo and F3, among others) are permitted on their specific event dates, which is different from turning up to swim independently.
How do I get to Dorney Lake by train?
The nearest station is Taplow on the Elizabeth Line, followed by a short taxi to the venue. Driving via M4 Junction 7 onto Lake End Road/Court Lane is the more commonly used route for race-day logistics.