Aerial view of two divers swimming in murky water in a lake in southern France in the middle of winter

aerial view two divers murky water lake south of france swimming winter cold water immersion visibility equipment training certification technique breathholding stamina endurance swimwear wetsuit thermals drysuit neoprene fins mask snorkel regulator diving adventure exploration travel destination scenery landscape nature outdoors tourism recreational activities leisure vacation water sports safety lifeguard emergency flotation device waves depth marine life environmentalism conservation