Entered the water by a slipway after it had got dark. Vis was not too promising at first, but by the time we got to the arch and dropped down it was breathtakingly clear. Moving through the cave under the arch was awesome - like being in outer space. Reminded me of the second dive on the Thistlegorm. Turned our torches off and the dark water phosphoresced. This was a thrilling dive - one of my best yet. Moving through clear dark water was almost like being back in the womb. Awesome.