About the Course

The Olympic 10km marathon swim will consist of six loops of 1.67 km each in a course that is shaped somewhat like a kidney bean.

The course will demand that the world’s fastest marathon swimmers provide their aerobic endurance, navigational skills, physicality, speed and strategic tactics. During the short legs on the course, the athletes will have to make four directional changes within 350 meters or so. If an athlete is boxed out or has poor position around these turns, then any advantages gained on the longer legs will disappear.

The feeding station is positioned right before these tight turns and athletes will undoubtedly have to feed fast in order to maintain their positioning in the pack.

The athletes will be swimming in the clockwise direction and their split times will be taken every lap as they pass through an intermediate timing gate near the start and finish structure. While the VIP seating is near the start and finish, spectators will be allowed – and encouraged – to stand around the course and take in the majesty of the world’s best open water swimming showcasing their skills and level of fitness only meters from the shoreline.

The finish should also see some position changes. As the athletes make three consecutive right shoulder turns before they sprint hard to the finish, their perspective will change on the last directional tangent which is oriented to the left. So it is right…right…right…left and then a quick 100-meter dash for Olympic glory.

In summary, the Olympic marathon swim course offers its own particular challenges:

  • few straight-line tangents in the course
  • relatively cool waters
  • pressure-packed ambiance of the Olympic stage
  • global media attention


The athletes must manage the course as well as:

  • an incredibly fast pace (1:04 – 1:12 per 100 meters without walls or rest for 10,000 meters)
  • the brute physicality of 25 closely packed competitors
  • tactical skills necessary for good buoy turns
  • the ability to pace, position and surge in a tight pack


These present real-enough tests for the Olympics athletes – many of whom will go on to complete channel swims and other open water swims around the world in extremely fast times.

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