In the early 1950s, Andy Cassell, a 9-year-old boy on the Isle of Wight in England, read about the Kon-Tiki expedition, the Norwegian explorer Thor Heyerdahl’s voyage across the Pacific Ocean on a primitive raft.

Andy began to dream of sailing, although it seemed an unlikely prospect: He had been born with malformed hips and no legs.

Still, he built a raft with pine logs he found on the beach, and his grandmother helped by fashioning a sail from a tablecloth and a mast from a clothesline pole. His mother allowed him on the raft, so long as he remained tied to the shore with a 60-foot rope. After a few weeks, he cut the rope.

Soon enough, he was racing a secondhand Albacore dinghy that his grandmother bought him. And at 18, Cassel (pronounced CAS-ul) won a national dinghy-sailing championship. He went on to become a skilled competitor in national and international races in various classes, including keelboats and yachts.

In August 1979, at the age of 37, he helmed a crew of six in the Fastnet Race, a roughly 700-mile yachting competition from southern England to Ireland and back, named for the Fastnet Rock, a rugged Irish islet in the middle of the course.

They set out in sunshine, but it wouldn’t last. A severe windstorm killed 15 sailors in what is now considered the deadliest race in modern yachting history.