Boston Light Swim Rules

By and large, the Boston Light Swim is governed by generally accepted practices for marathon swims, or "English Channel rules" as laid out by the Marathon Swimmers Federation. Specifically, BLS swimmers must adhere to the following or risk disqualification:

  • No wetsuits

  • No Fastskins or high-tech suits; only basic, textile suits are permissible.

  • No intentional contact with the boat or another person

  • Use of only one bathing cap (one will be provided to you and for safety/visibility reasons, you MUST wear the cap we give you)

  • Absolutely no music players (music is fine on the boat if your pilot is OK with that, but you may not wear an audio device in the water)

  • Use of only one textile suit that does not:

    • extend onto the shoulder

    • extend below the knees (jammers are OK)

    • provide buoyancy or heat retention

Feeding is permitted (and encouraged), and the application of anti-chaffing substances such as zinc oxide lotion, Vaseline, or Channel grease are allowed. (Check with your boater about whether or not these potentially messy substances are permitted on his/her boat and plan accordingly.)

All swimmers must swim alongside their guide boat. You WILL be disqualified and removed from the race if you are observed swimming behind the boat. This is a safety requirement. Swimmers must keep within 10 to 20 feet of the port or starboard side of the boat. Your boater will be made aware of these rules, too.

There is a strict 5-hour time limit on the course. If you have not completed the event by the expiration of this time limit, you must board your escort boat and motor into shore.

All swimmers must be 18 years of age or older.


Relay teams (which may be comprised of 2, 3, or 4 swimmers) are governed by the same attire and general rules above, and are permitted to use a ‘helter skelter’ approach to their swims, meaning that swimmers are permitted to switch out as frequently as they want. You may swim in any order you want (and are welcome to mix it up throughout the swim), for any length of distance or time. The only set rule is that your team may not have more than one swimmer in the water at a time, so the swimmer in the water must exit the water when the next swimmer enters the water. Relay teams are encouraged to finish the race as a team (all together across the finish line).