Mark Tully discusses our longing for the sea with National Poet of Wales Gwyneth Lewis, who spent a year on a disastrous round the world voyage. Despite the danger and the loneliness, she still longs for the sea, and reads a new poem "Sea Virus". Lewis is a committed Christian, and she talks about how the experience of being alone on a vast ocean has strengthened her spiritual belief. Other poets in the programme include the contemporary Welsh poet Menna Elfyn, who speaks of the sea opening her eyes; and the Anglo-Saxon seafarer from before the Tenth Century. The music includes Britten's Sea Interlude: Dawn, Charles Trenet's evocative song of the 40s "La Mer", and a Bach cantata in which he evokes a storm. Producer: Elizabeth Burke A Loftus production for BBC Radio 4.