Martin Strel is a Slovenian long-distance swimmer who was inducted as an Honour Swimmer in the International Marathon Swimming Hall of Fame . Strel was born on 1 October 1954 in the town of Mokronog, in the Slovenian region of Lower Carniola, then part of the Socialist Federal Republic of Yugoslavia. He is best known for completing stage swims along the entire length of the Danube River , the Mississippi River , the Yangtze River , and the Amazon River . He is a member of the 24-hour club . He serves as an Ocean Ambassador of Ocean Recovery Alliance . He operates open water swimming tours with his son Borut Strel at Strel Swimming Adventure Holidays and planned the Strel World Swim , a solo stage swim around the globe.