Snorkel at two famous Bermuda shipwrecks, each on the edge of a surrounding reef loaded with colorful coral and fish. This beautiful reef is also treacherous and has more than 300 shipwrecks to prove it. The Constellation, a wooden-hulled four-master built in 1918, had a checkered history before sinking as a cargo boat in 1943. Scattered remains of the Montana went down more than 150 years ago, but her iron paddlewheel frames remain intact.