Race Details

Distance: 1 mile

Date: Saturday, June 6, 2015 (Rain date is Sunday, July 19)

Start: 8am

Check-in: 6:45am – 7:30am

Location: River Dock (near Arthur Fiedler head statue by the Hatch Shell on Esplanade)

Description: One-mile loop course between Harvard and Longfellow Bridge. Water start.  Please see maps.

Fees: $35 before April 25, $40 before May 16, and $45 before May 31. USMS membership is a requirement and a one-day membership can be purchased as part of the registration process for $10.

Participant cap: 150 swimmers

Registration: As part of the registration through Active.com you have the option to purchase a one-day USMS membership, if you are not already a USMS member. Only pre-registered swimmers are allowed to participate and we cannot accommodate substitutions. The USMS sanction # for this is 025-W002.

  • Only pre-registered swimmers are allowed to compete.
  • Water temperature: Has historically been 70 degrees or above.
  • Wet suits are allowed, unless the water temperature exceeds 78 degrees (per USMS rule).
  • This swim is not for novices; it is for experienced open-water swimmers only. At a minimum you should be able to swim one mile comfortably in under 40 minutes.
  • USMS membership is required. Day-long membership is $10 and can be purchased as part of the online registration.
  • Age requirement: 18 years minimum
  • Kayakers will provide support during the race
  • Fluorescent swim caps will be provided and must be worn for safety reasons
  • Mandatory Athlete check-in from 7:00am to 7:45am, need to bring ID and USMS membership card if already a 2015 member
  • Pre-race announcement at 7:45am
  • Start 8am
  • Bag-check available
  • The rain date will be Sunday, July 19.


  • This swim is not for novices; this event is for experienced open-water swimmers only. We ask that you either list at least one open water race you completed during the last 2 years or that you certify that you swim the distance of at least one mile in the pool several times a week. You should be able to swim one mile comfortably in a pool in under 40 minutes.
  • The race is dependent on weather conditions and may be canceled under adverse conditions. Swimmers may encounter random jetsam and flotsam in the river.


  • In the even of heavy or prolonged rainfall, the swim might be canceled. In that case, we will send out an e-mail the day before the race and have a notice on this website.


  • Awards, goodies, race packet and post-race refreshments
  • Bragging rights for having swam a mile in the Charles River!


We suggest you arrive by public transportation, biking or walking. The closest MBTA station is the Charles/MGH station on the Red Line or Arlington or Copley Station on the Green Line. Volunteers will greet persons crossing the Arthur Fiedler footbridge or the Charles/MGH footbridge. Pay parking is available at the Boston Common garage. Rates and directions are available here.