It is not technically an open water swim, but the 24-hour Bad Radkersburg charity swim at Parktherme in Austria surely counts as a long-distance swim.
108 solo swimmers (69 men and 39 women) and 81 five-person teams – and their coaches and supporters – crowded the pool deck and lanes during this year's annual race in November race. Each swimmer uses an SMC Active Chip system to keep track of the number of lengths swum. The chips gave a detailed record of 140,103 lengths of the 50-meter pool or 7,005.15K (4,352 miles) cumulatively swum.
Mauro Giaconia, a 24-hour swimming specialist from Palermo, Italy swam 69.6K (43.24 miles) over the 24-hour period for the best performance among the men. Caroline Rakowitz, an endurance athlete from Spielberg, Austria swam 61.7K (38.3 miles) to top the women. ASKÖ SV Enns team swam 105.3K (65.4 miles) for the furthest distance among the 81 teams.
Hydrating and fueling is, of course, important and aided by the midnight pasta buffet and the breakfast. The swimmers went through 500 liters of Isostar sports drinks, 1,000 Isostar bars, plenty of Isostar chocolate cake, and boxes and boxes of Nestle breakfast cereals provided by More4Sport.
The swimmers and support crews were entertained through the evening by a dance company, a DJ and music from a professional ensemble, ranging from Broadway musicals to gospel and pop.
Bad Radkersburg is a small town of only 1,940 people in the southeastern part of Austria, but it is well-known for its spa and thermal springs.
12-hour and 24-hour pool swims are held throughout Europe, including in Italy, Switzerland, Germany and Monaco. Many 24-hour events are also held throughout the world, including Australia where a series is organized under the 24 Hour Mega Swim brand - see below:
As a frame of reference, two of world's top professional marathon swimmers – Paul Asmuth and James Kegley – partnered up at the famous 2-person Lac La Tuque 24-hour professional relay in Canada in 1980. In a lake with 16°-17°C water, Paul and James swam a total of 111K (69 miles or 34.5 miles each), alternating with each other every mile.