Water where you can't quite touch bottom

Dannie Abse, when castaway on the Desert Island Discs of 27 August 1977, said of his poetry: "It's more conversational than lyric, especially in latter years, and I have said that I would like my poetry to be lucid, or apparently lucid, to be a deception in fact, to be as translucent as water, but when you got into the water you couldn't, as it were, quite touch bottom."