Documentation Requirements

MSF Documented Swim submissions should include a diverse portfolio of data and documentation, which provides a complete story and compelling evidence for the swim. See for numerous examples of well-documented swims.

The following items are required for documentation submissions (unless specifically noted as “optional”).

Swimmer Biographical Data

  • full name
  • age on date of swim
  • nationality
  • city & country of residence
  • previous marathon swims completed

Support Personnel

  • Names of everyone involved in the swim, and each of their roles.

Route Specification

Latitude/longitude coordinates and name/description of:

  • start location
  • finish location
  • all intermediate waypoints necessary to connect the start and finish via the shortest swimmable path

Please note: Swim routes governed by established local sanctioning organizations are not eligible for MSF Documented Swims, unless there is consent from the relevant organization.

Swim Distance

For official swim distances, MSF recognizes the route distance (straight lines or line segments on a map), not the track distance (sum of GPS track).


Swim Log completed by independent observer

Click here to download the MSF standard observer report.

  • Start time and date (include local time zone)
  • Finish time and date
  • Elapsed time of swim (hours, minutes, seconds)
  • Log of regular timestamped observations of:
    • GPS location (latitude, longitude) - satisfied by complete GPS tracking data
    • Stroke rate (strokes per minute)
    • Water temperature
    • Air temperature
    • Wind speed or force
    • Wave height
    • Subjective description of conditions
    • Other notable events (e.g., wildlife encounters)
  • Narrative account of swim. Optional but recommended.

The specific format of the Swim Log is left up to the observer, as long as the data requirements are fulfilled.

Please note: The Observer should not be the only witness to the swim, and should not be serving simultaneously as the swimmer’s support crew.

GPS Tracking Data

Original/raw data from GPS tracking device such as a SPOT Tracker, Garmin watch, or smartphone app. Accepted data formats: GPX, TCX, CSV, KML. We recommend using at least two tracking devices simultaneously in case one fails.

Photos and Video

A representative collection of images and video footage, taken at various stages of the swim.

Swimmer Narrative

Swimmer’s first-person account of swim planning & execution.
Optional but recommended.

Other Supporting Data

Optional but recommended.

  • Marine buoy readings during the timeframe of the swim (e.g., NOAA National Data Buoy Center).
  • Local tide and current predictions for the timeframe of the swim.
  • Media coverage of swim (newspaper articles, TV segments, etc.).

How to Submit Documentation

  1. Pay the ratification fee.
  2. We will contact you with further instructions.