We recently spent a long weekend in a holiday cottage down in Cornwall. Jack came along too. One afternoon we took him down to the coast near Par to walk along the beach.
Previously he'd indicated that having sand underfoot was the main point about beach walks, the sea only provoking minimal investigation. He seemed quite interested in the sea this time, enough to indulge in some fairly enthusiastic paddling. Perhaps the abundance of weed and rock pools drew him in. No swimming though, he still draws the line firmly at armpit depth.