Somewhere up there rocks jut and grasses hang. They look close but feel remote, the water’s surface an indifferent sky. Feet dangle from it, kicking. Hands thrash. A kid with a mask and snorkel dives down a couple of meters, his willowy body beats the water with explosive energy. Time is short—a single breath. While we hover far below, in an eternity limited by the air in our tanks. We are covered in moss and sink into the stone.