We would like to welcome all of you to our Midweek Triathlon at Dorney Lake. We wish all of you who have entered this event good luck with your final preparation and training for the race, We request that you read fully all the details outlined below.

Dorney Lake, Eton College Rowing Centre, off Court Lane, Dorney, Windsor, Berkshire, SL4 6FJ 

Directions & Parking
Once you have found the venue you will be greeted at the main gate and shown where to park.

Registration & Transition are located at the start end of the lake as shown on the map below.

Site Map

Evening Overview
4.45PM – Registration, Transition & Venue Open to competitors
5.45PM – Registration & Transition Closes.
6-6.30PM – Competitor Starts


Registration will take place in the race village and is the large red tent on the plan above.

At registration you will need to provide photo ID confirming your identity and will then receive your timing chip which will allow you entry to Transition.

COVID 19 Restrictions

Due to Covid-19 restrictions a number of key changes from a normal event setup our required and are highlighted here separately for clarity.

  • No supporters are allowed in the venue – only athletes and marshalls will be allowed on site. We are open to having more marshalls on site.
  • Antibacterial hand gel stations on entry to transition
  • Masks to be worn in transition during setup – not required during event.
  • Socially distanced registration process – please maintain 2m from our volunteers.
  • No on the day briefing – video sent out 48 hours before hand.
  • The event will be individual start.
  • The event is non drafting with a drafting distance of 10m.
  • No feed stations on course – take what you need out with you.
  • No award ceremony or results on site – results will be available to view live online and awards announced electronically/prizes by post.


No supporters are allowed at Eton Dorney for events due to Covid 19 restrictions but we do have need for a few more Marshalls. Drop us an email if you have somebody who would like to attend and we can likely find them a suitable role.

Transition & Bike Racking

Competitors are able to rack their bikes prior to the event between 4.45PM-5.45PM. As soon as you have completed setup please make your way over to the athlete holding area by the swim start.

Competitors will select their own racking placement on the day, please note that you should never touch or move another competitors bike, if you require assistance to rack ask a Marshall.

All bags should be stored at the edges of transition out of the way of other competitors.

If this is your first triathlon we suggest you take 5 minutes to watch the below video on how to set up transition.


You will then be required to walk across the tarmac bike course to the grass area in front of the swim start. This walk is on a mixture of grass and tarmac and can either be done either in flip flops or barefoot. All competitors need to make their way to the swim start prior to event start due to the crossing of the bike course.

Race Briefing

The race briefing will be conducted electronically and sent out approx 48 hours prior to the event start. Please ensure you fully watch this video so you know how the event will be managed on race day.

Start Times
The race is a individual start event with each participant running into the water and starting approx 10 seconds apart.

You will be whipped into the correct order for starting on race day with distance swimmers starting first followed by triathletes.

Head Torches/Bike Lights

The time of sunset is 7.30pm with twilight extending until 8pm. This means that for those starting late it will be getting dark as you approach the end of your run. You may wish to take a head torch out with you on the run and for safety purposes you may want to have a rear light fitted to your bike. Head torches will also make it easier for packing up in transition (this area is illuminated) and making your way back to your car.

Timing System

The timing system for our events uses an electronic chip timing system.

You will be supplied with a race number which will be either

  • pinned to your front or
  • attached to a race belt and displayed rear on the bike, front on the run.

Your individual start time will be recorded by the device when the Marshall tells you to start, and then compared to your own individual finish time. Split times will be provided. All results will be available online and we request you don’t hang around for too long to compare results.

The Rules

Please take the time to read the British Triathlon competition rules.

The Course 

The Swim

Consists of a looped swim for swimmers and a single lap swim for triathletes in an anti clockwise direction.

Super Sprints will head left at the first yellow cylindrical buoy

Sprints will turn left at the first red cylindrical buoy

The Bike 

Course will consist of Bike course consists of a 4.65km anti clockwise loop.

Super sprints will complete 3 laps

Sprint distance athletes will complete 5 laps.

We have static marshals at key locations on the bike course and they will report you if you are seen to be breaking these rules. One of their key tasks is to identify anyone gaining UNFAIR ADVANTAGE through drafting.


The Run

consists of an out and back course.

Super Sprint distance athletes will complete complete one our and back loop.

Sprint Distance athletes will complete two out and back laps.


Awards will be sent out in the post following the event and placings announced via email and social media online.

Awards will be issued on the following basis.

Overall 1-3 Male & Female in All Races.

Age group awards for the sprint Triathlon – first in each cat, Senior 20-39, Vet 40-49, Super Vet 50-59 & Vintage 60+.


Racing And The Highway Code
Whilst this is a closed road event please do not take undue risks not only to yourself and other athletes,

Under BTF sanctioned events you must not leave equipment or personal gear on the race course. Which includes littering out on the course.Yes, a gel wrapper is considered equipment under this rule.It is an offence under UK law to drop litter in any place open to the air, including private land, so if you are seen dropping litter on the course you will be automatically disqualified.Put used gel wrappers and the like in your bike jersey and discard them in transition. If a water bottle is launched from your bottle cage when you hit a bump in the road, turn around and pick it up before it becomes a hazard to another rider.