Big East Triathlon – 23rd May 2021

The Big East Triathlon


The Big East Triathlon has become a classic within the triathlon community.

The event consists of a Challenge event with an 800m swim in the River Blackwater, a 43km cycle in the peaceful Essex countryside and a 10km lapped run based around Bradwell, the sea wall and marshes passing the historic St Peters Chapel.

The Middle Distance event features a 1.6km swim, 82km cycle and finishes with a 20km lapped run.

Please note that is a tidal river and will be more challenging than a typical open water or pool swim. Wetsuits are not compulsory. Aquabike options are also available.

Swim Cut-Off is strictly 11:00AM

Cycle Cut-Off is 17:00

The triathlon will begin at 9:25am. All events will take the style of a rolling start with athletes starting at short intervals with the fastest athletes starting the swim first. This is based on the estimated finish time given at the checkout when entering. This format may change depending on the Covid restrictions in place at the time.

Many people are understandably nervous regarding entering events again and we want to assure you that we take every measure we can to organise a safe, socially distanced event. To see this in action watch our video Covid-19 Safety at ActiveTrainingWorld Running and Triathlon Events.

  • Location: Bradwell Marina, Waterside, Bradwell-on-Sea, Essex CM0 7RB
  • Distances: Challenge Triathlon = 800m swim, 43k bike , 10k run | Middle Distance Triathlon = 1600m swim, 82k bike , 20k run | Challenge Aquabike = 800m swim, 43k bike | Middle Distance Aquabike = 1600m swim, 82k bike
  • Minimum Age: Challenge – 17yrs | Middle Distance – 18yrs (ages on 31/12/2021)
  • Activity: River Swim, Cycling & Running

  • Open to: Solo participants and  relay teams

  • Entry Fee: 6 options from just £52 per person (Details below)

  • Event Cancellation Policy: We want you to book with confidence so, if this event can no longer go ahead, and an alternative date isn’t found, you will be offered a virtual run or a refund of your entry fee. (Booking fees are non-refundable)
  • Additional Fees: A 6% booking fee will be added at the checkout
  • Event Organiser: Active Training World
  • Organiser Email:
  • Official Event Website: None



Registration opens from: 8:00am

Here you will receive your race number, timing chip and stickers for your bike and helmet plus a swimming hat.

The day license for Non-BTF members is included in the entry price.

There will be an online race briefing made available before the event, it is mandatory to have watched this as there will be no pre-race briefing on the day.

Please arrive in sufficient time to collect your race number.


Swim: The event consists of a 800m/1.6km swim in the River Blackwater and the Swim Cut-Off is strict due to the changing tide. Wetsuits are not compulsory.

Swim Course Map

Bike: The cycle course takes athletes out of Bradwell Waterside and onto the quiet, scenic roads of the Dengie Peninsula. Here you will pass through small towns and villages with traditional weatherboard homes, negotiate the Burnham Bends and experience a fast and flat course over the marshes. Challenge distance athletes will complete 1 lap of the course and Middle distance athletes 2 laps.  Cycle Cut-Off is 7 Hours 30 Minutes from the Start Time.

Challenge Distance Bike Course – 1 lap (43km)

Middle Distance Bike Course – 2 laps (82km)

Run: Athletes will run out of Bradwell Waterside past the old airfield and RAF memorial before heading through Bradwell-on-Sea towards the coast. St Peters Chapel will become visible as you retrace the steps of religious pilgrims from as far back as 654AD. The course then follows the sea wall, popular with walkers, before passing the decommissioned nuclear power station and returning to Bradwell Waterside. Surface is a mixture of paved roads, trail, grass and gravel track.

Challenge Distance Run Course
Middle Distance entrants complete 2 laps

Swim – tidal river | Bike – fast, flat road | Run – a mixture of paved roads, trail, grass and gravel track.

We actively welcome support and involvement from local communities, businesses and individuals. If you would like to find out more about marshalling, sponsorship or group bookings please contact us at the address below.

Spectators are currently not allowed. If this situation should change we will update this page.

If you would like more info on this event please use the email address below:


Need help with your running? Whether this is your first triathlon and you want to know how to prepare, or you are looking to smash your personal best – following a training plan will increase your chances of achieving your goals.

Visit the ATW Shop to see our available training plans.


Custom designed medal for all finishers! 

Prizes for Top 3 Men &  Top 3 Women overall

Plus prizes for Top 3 Men & Top 3 Women in age 40+ category

There will be no prizegiving on the day but you will be able to collect your medals.

There will be full results on the chip timing website both overall and by category.

It is important that you are fit to run and have not experienced any Covid-19 symptoms in the 14 days leading up to the event.

Race Numbers
Please wear your number pinned to the front and back of your vest or alternatively, using a race belt, rotate the race number to the back for the bike leg and the front for the run leg.

Parking will be located on site at Bradwell Marina. There is strictly no parking on the road or the marina entrance road. You may be charged £1 to park for the day. Car Parking opens at 08:00AM.

Changing Facilities
We will not be providing a changing area, therefore please come changed and ready to race.

Baggage Drop
There will be an informal baggage drop area for you to leave any belongings within the transition area.

There will be toilets available.

Water Station
Water will be provided on a Covid-safe way on the run route and at the finish. Full info will be provided in the final details.

Dogs & Buggies
No dogs and buggies allowed.

If you are unable to attend due to illness, injury, family bereavement, jury service you will only be eligible for a refund on production of official evidence: Positive Covid-19 test result, Doctor’s note, Death Certificate etc.

Event Cancellation
If the event should have to be cancelled due to reasons beyond ATW’s control (for example, severe weather, local or national lockdown) entrants will be given a range of options to choose from, which will include a refund of their entry fee (less the booking fee).

By entering this event you agree to the below terms and conditions:

Your details will kept in accordance with the Active Training World Privacy Policy

Your name, date of birth and email details will be onto the chip timing company. Personal details will be deleted 1 week after the event.

Where specified on the booking form any medical information will be passed onto the medical team present at the event. 


1) I am over 17 as at 31/12/2021 (Challenge Distance) or over 18 as at 31/12/2021 (Middle Distance). 

2)  I declare that I am medically fit to compete & understand that I do so entirely at my own risk.

3) I understand that I enter the race at my own risk and that no person(s) or organisation(s) will be held responsible for any accident, injury or loss to myself, prior to, during or after the event.

4) I understand the organisers reserve the right to alter the arrangements and conditions, should circumstances require.

5)  By entering this event, I accept BTF rules.


The event is being officially timed by Event Chip Timing and the results will be available on the day at

Ticket Details

  • If this is your first registration on our new booking platform but had an ATW account previously, your old ATW log in details are now invalid and a new account will be created for you when you book your first event without logging in.
  • If you are booking more than 1 place, please ensure that you complete the individual details for each attendee accurately answering all the questions on their behalf.
  • Relay entries should be completed with lead entrant’s details only. Additional team members’ details will be taken at Registration on the day
  • The BTF Day License for the event is included in the price of a Non BTF Entry
  • Prices do not include 6% booking fee. This will be added at checkout.
Details Price Qty
Challenge Entry Non BTF Member£68.00 (GBP)*  
Challenge Entry BTF Member£62.00 (GBP)*  
Challenge Relay Entry Non BTF Member£78.00 (GBP)*  / bundle 
Challenge Relay Entry BTF Member£72.00 (GBP)*  / bundle 
Challenge Aquabike Entry BTF Member£52.00 (GBP)*  / bundle 
Challenge Aquabike Entry Non BTF Member£58.00 (GBP)*  / bundle 
Big East Triathlon Middle Entry Non BTF Member£91.00 (GBP)*  
Big East Triathlon Middle Entry BTF Member£85.00 (GBP)*  
Big East Triathlon Middle Relay Entry Non BTF Member£101.00 (GBP)*  / bundle 
Big East Triathlon Middle Relay Entry BTF Member£95.00 (GBP)*  / bundle 
Big East Triathlon Middle Aquabike Entry Non BTF Member£81.00 (GBP)*  / bundle 
Big East Triathlon Middle Aquabike Entry BTF Member£75.00 (GBP)*  / bundle 

Price does not include booking fee

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