Porth yr Ogof cave resurgence

These photographs show the resurgence of Porth yr Ogof cave in the Brecon Beacons, South Wales. A resurgence is where water returns to the surface after traveling underground through a cave. These were further test shots using a D80 camera in an Ikelite underwater camera housing. Some utilise split level photography, where the camera is partly submerged, while others look towards the surface from below through 'Snell's Window', an optical phenomena, in which the world above water can be seen from below.