The Manhattan Island Marathon Swim (MIMS) is the longest regularly held swim race in the world.

Photo: The skyline of New York

Held annually, the MIMS “race” is a full counter-clockwise circumnavigation of the island of Manhattan, starting and finishing in Battery Park City on the Hudson River. It total, this circumnavigation is 45.8 km.

The first known circumnavigation swim around Manhattan was in 1915 when Robert Dowling, Jr. (not to be confused with Robert Downey, Jr) completed the swim in 13 hours 45 minutes. The first official Manhattan Island Marathon Swim “race” was held on September 14, 1982 with 12 swimmers. The MIMS has continued as an annual event since then and it is recognised as one of the 3 swims in the Triple Crown of Open Water Swimming (alongside the English Channel and the Catalina Channel in Southern California).

The swim generally takes 8 to 10 hours, however, some swimmers get it done a little faster. The course record is 5:44:02 set by Oliver Wilkinson of Australia in 2011. The female course record is only 45 seconds slower at 5:44:47, held by Rondi Davies from New York.

You may notice that the record holders were swimming at about 8km / hour which is faster than Olympic swimmers in the 100m freestyle final – this is because the swim is current assisted. It is important to start at the right time, swim with the tide, and get to the point where the Harlem River joins the Hudson River before the tide changes and pushes the swimmer back to where they came. Additionally, the tides can vary in strength. For example in 2011, the record was broken three times in the day, which says something about the strength of the current as well as something about the strength of the swimmers.

The swim in 2014 was the 33^rd annual “race”. The Manhattan Island Marathon Swim has been completed by more than 600 swimmers prior to 2014.