River

Flowing water. Depth changes without warning, levels respond to rain within hours, and the current is a factor in every swim.

7 published records
Spot	Type	Region	Max depth	Walk	January	August
River Wye at Symonds Yat A wide, slow, meandering reach below a limestone gorge, with a shingle beach and a ferry that has run on a rope since the 18th century.	River	Herefordshire / Gloucestershire border, England	3.5 m	3 min	5.5°	18°
Upper Rhine at Rheinau A broad, fast, island-fringed stretch of the Rhine where the standard local swim is a 1.2 km downriver drift between two bridges.	River	Schaffhausen, Switzerland	6.5 m	5 min	4°	19°
River Wharfe at Grassington A limestone-bedded Dales river with a long shallow run and a deep pool under the old packhorse bridge — the Wharfe was England's first river to get inland bathing-water status.	River	Yorkshire Dales, England	3 m	8 min	5°	16.5°
Berounka at Branov A slow, sandy-bottomed river bend beside a wooden ferry landing, with the warmest summer water of any Czech river swim on this list.	River	Central Bohemia, Czechia	2.2 m	2 min	2.5°	20°
Verzasca at Lavertezzo Green-white granite pools under the Ponte dei Salti, the clearest river water in Switzerland and one of its most dangerous, because clarity makes depth impossible to judge.	River	Ticino, Switzerland	8 m	3 min	5°	15.5°
Soča at Bovec The most photographed river in the Alps: an unnervingly clear turquoise channel over white limestone, cold enough in August to make a wetsuit worth carrying.	River	Julian Alps, Slovenia	3.2 m	12 min	3.5°	14.5°
River Dart at Newbridge A wide, shingle-bedded bend of the Dart where a medieval bridge pins the flow into a long, slow pool — the most forgiving river entry in the Dartmoor ring.	River	Devon, England	2.6 m	4 min	6.5°	17.5°

Before you get in

Cold water is the one hazard that applies everywhere in this library. Below 15 °C the gasp reflex can make you inhale water involuntarily within seconds of immersion; below 10 °C, unacclimatised swimmers lose the ability to swim effectively within minutes. Enter gradually, keep your first session under five minutes, never swim alone, and get out while you still feel fine — the afterdrop continues after you leave the water.