Pre-Event Information for Swimmers

Please check out the Schedule of Events page for more information about times and locations for events related to this year’s Boston Light Swim.

Safety and Rules Information

Safety is our top priority! All rules and regulations exist to make this marathon swimming event the safest it can be.


  1. We have a strict 5-hour limit on the course. All swimmers must exit the water at 12:30 p.m. if they have not yet finished. No exceptions. This is part of our permitting and insurance requirements, so we are sorry, but there's simply no flexibility on this one. Ignoring the request to get out will get you banned from all future MOWSA-sanctioned or sponsored events.
  2. Swimmers may not touch escort boats or crew members during the swim (unless it’s a relay). 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. See our rules page for more specifics on what is and isn't allowed.
  3. While in the water, swimmers must wear the numbered, fluorescent caps we provide.
  4. Escort boats must display their swimmers’ number and the red/white diver down flag. (Please return these flags at end of your swim. A volunteer will be stationed at the BHYC to collect them from you as you disembark.)
  5. No wetsuits are allowed.
  6. Kayaks may only be used as secondary support and only with prior approval by your boater; in the event of an emergency or event cancellation, the accompanying escort boat must be able to accommodate the kayak and kayaker for the ride back to shore.

Safety Boats

  • There will be three event safety boats on the course. One will be in the front, one in the rear, and one patrolling the middle.
  • The U.S. Coast Guard will be present, and they have the authority to cancel the event for any reason.

Swimmer Health and Safety

  • Crew and boaters: Watch your swimmer for signs of hypothermia, heatstroke, dehydration, exhaustion, injury, etc.