China Beach, San Francisco. Photo by Ryan Willis.
The Marathon Swimmers Federation (MSF) is dedicated to developing and promoting the sport of unassisted solo marathon swimming (ultra-swimming), by:
- Maintaining authoritative historical records of successful swims.
- Preserving the sport’s spirit and traditions by articulating general rules and standards.
- Publishing and ratifying documentation of independent swims.
- Fostering connections and information sharing among the global practitioners of ultraswimming.
- Recognizing outstanding swims and contributions to the sport.
Meet the MSF Team and Core Group.
Latest Articles at Ultraswimming News
Comprehensive, verified swim results and records
77,000+ swims by 25,000+ swimmers, 1875 to present.
Solo swim ratification service
Independent solo marathon swims, documented according to the highest standards.
- Documentation Requirements
- Standard Observer Log + Instructions
- Past Documented Swims: 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021
Rules of Marathon Swimming
Standards for unassisted swims in any body of water
Regional Swim Calendars
Annual, organized swim races. Maintained by locals
The source for official MSF merchandise
- Photo Calendars
- Swim Caps