Chepstow, Wales, United Kingdom

NDAC Chepstow

The National Diving and Activity Centre near Chepstow on the Welsh side of the River Wye is a flooded former limestone quarry and the deepest inland dive site in the United Kingdom, reaching 80 metres at its lowest point. The site is a major training facility for technical, recreational and rebreather divers, with multiple submerged platforms at 6, 12, 22, 30, 50 and 70 metres, and an extensive collection of attractions: a Wessex helicopter, a SeaCat catamaran, several boats, training platforms, a tank and decommissioned aircraft fuselage. Marine life is freshwater: rainbow trout, brown trout, perch, roach, signal crayfish and ducks. Visibility is consistently good, often 8 to 15 metres because of the limestone geology and limited surface flow, and water temperatures range from 4 degrees Celsius in winter to 18 degrees in late summer at the surface. Pronounced thermoclines descend from 12 metres into colder water, with the deepest layers at 4 to 6 degrees year-round. The centre runs technical courses, rebreather training, accommodation, a cafe and air, nitrox and trimix fills.