10,000 - Distance covered in metres by competitors in the Olympic Marathon Swimming competitions. 

2008 - Year when marathon swimming, often called open-water swimming, made its debut on the Olympic Programme at Beijing.

45 - Number of countries that have competed in Olympic marathon swimming. 

36 - Age of Spyridon Gianniotis of Greece when he claimed silver in this event at Rio 2016.

23 - Age of Florian Wellbrock of Germany when he won gold in marathon swimming at Tokyo 2020.

19 - Age of Larisa Ilchenko (RUS), the youngest medal winner in Olympic marathon swimming. She won gold at Beijing 2008.

13 - Number of countries that have won Olympic medals in marathon swimming.

7 - Number of years after being diagnosed with leukemia that Maarten van der Weijden of the Netherlands became the first men's Olympic champion in marathon swimming.

3 - Number of gold medals won by the Netherlands in marathon swimming: two in men's competition - Maarten van der Weijden in 2008 and Ferry Weertman - and one in women's - Sharon van Rouwendaal - in 2016. 

2 - Number of swimmers with multiple medals in Olympic marathon swimming. Thomas Lurz of Germany collected bronze in 2008 and silver in 2012, while Sharon Van Rouwendaal (NED) won gold in 2016 and silver in 2020.