David Lewis might be the greatest explorer you've never heard of. Born in England in 1917, but raised in New Zealand and Rarotonga, Lewis' exploits included climbing 19 South Island peaks, kayaking solo around the North Island, circumnavigating Earth in a catamaran, and being the first person to sail to Antarctica alone.  Journalist Ben Lowings has written a biography of the sailor, adventurer, doctor and Polynesian scholar called The Dolphin.