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A Boston Tradition Since 1907

The oldest open water marathon swim in the U.S. and affectionately billed as the “Granddaddy of American Open Water Swims,” the 8-mile Boston Light Swim has been a local tradition since 1907. Participants begin the race in the water at America’s first lighthouse, the Boston Light on Little Brewster Island in the outer Harbor. The course continues past George’s Island and Rainsford Island, then along Long Island (and past where the Long Island Bridge used to stand), and around Thompson’s Island. Swimmers come ashore at the historic L Street Bathhouse in South Boston, home of the world famous L Street Brownies and the L Street Ice Swimmers.

This swim is perfect for seasoned cold water ocean swimmers and those who are working up to longer cold water swims. Many swimmers in the past have used this 8-mile, non-wetsuit swim to prepare for an English Channel crossing.

Come join us for a fun, fast marathon race in unpredictable, challenging, and totally fun conditions.

John DaPrato from New York got inked after finishing the 2010 Boston Light Swim! Where will you go next after you finish this swim?


This is a United States Coast Guard and Massachusetts Open Water Swimming Association permitted event.

Thank you to our 2017 Event sponsors and partners: Boston Harbor Yacht Club, Ultima Replenisher, DRINKmaple, Castle Island Brewing Company, FINIS, and the Curley Community Center. If you’d like to sponsor the Boston Light Swim, please contact Race Co-Directors Greg O’Connor and Elaine Howley. (goconnor AT massopenwaterswimming DOT org) (ehowley AT massopenwaterswimming DOT org)

Future Boston Light Swim Dates:

All swims are on a Saturday

2018: August 11th @ 7:30 am

2019: August 17th @ 7:30 am

2020: August 22th @ 8:00 am