Founded in 1975, we are a group of passionate volunteers dedicated to safe adventures in our Great Lakes that honour the traditions of marathon swimming. We observe and ratify escorted but unassisted marathon swims in Ontario waters, and we curate a history of swims in our waters that meet these standards.

Swim with us! Tell us about yourself, your swimming, and your planned swim.

Once you've completed these steps, we'll be in touch with you about fees, timing, and logistics. You will need to find boats, a pilot, and crew, but we can help! We'll assign you a swim master who can guide you through these steps, and who will serve as the official observer on your swim. We're a safety organization, so our primary focus will be helping ensure a safe crossing for everyone involved, so we'll ask for some more details in the following forms. Please work with your doctor or medical professional to complete our medical evaluation. We'll also ask you to sign a standard liability disclaimer, and to acknowledge our code of conduct.

Before your swim, we'll ask for evidence of a trial swim in comparable conditions to your proposed route, completed without aids or pacers, with your coach or team leader present, and generally also observed by your designated SSO swim master. The aim of this trial swim is to show us that you can cover a substantial portion the intended crossing distance at a reasonable pace, without undue fatigue, and using your intended feeding plan. Aim to get this trial swim done no later than a few weeks before your proposed swim. A successful trial swim is ultimately a matter of our judgement, but in general we're looking for the swimmer to cover 16km in well under 7 hours.

Before your trial swim, we also want to see evidence of sufficient preparation, so we'll ask you to submit the following form (or a reasonable equivalent, such as annotated Garmin or Strava logs) to your swim master:

For Lake Ontario swims that end in Toronto, there are some additional challenges (and associated forms) involved in traversing very busy waters. Those forms and resources are available here: