Photo Illustration by Elizabeth Brockway/The Daily Beast/GettyCarl Allen knew something was missing. For decades, the wealthy businessman had been obsessed with the wreckage of the Maravillas, a 17th-century Spanish ship he was convinced had crashed off the Little Bahama Bank. He’d already purchased a small island in the Bahamas and a 164-foot yacht to assist in his search, but he needed something that would let him dive deep—as deep as a 400-year-old boat could sink.So four years ago, he dragge