▶ Entering the caveYour browser does not support this video.Entering Source du Durzon. The narrow, uneven entrance clearly shows why a DPV is useful here, but also why the first section requires careful manoeuvring.© Ron Freijer
▶ Exiting the caveYour browser does not support this video.Hans and Ron exit Source du Durzon. On the way out, the low, irregular final passage shows how carefully the diver and DPV must be positioned.© Ron Freijer