LONDON — We all have hobbies we enjoy. Rick Stanton’s just happens to be scuba diving into cold, lightless, claustrophobic, dangerous caves. Stanton and his diving partner, John Volanthen, have been identified in the British media as the two British divers who first discovered the 12 children and soccer coach trapped in a cavern in northern Thailand. In the dramatic video footage of the moment when the divers reach the group, nine days after they disappeared, a diver with a British accent is heard talking to the group. “How many of you? Thirteen? Brilliant,” he says, as a beam from...