I learned to dive in Tobermory, Canada, the site of Fathom Five National Marine Park in Lake Huron. In this small park, literally dozens of 150-200- year-old shipwrecks lie at the bottom of the lake. In some cases, they are almost stacked on top of each other, a testament to the storms of November that were immortalized by Gordon Lightfoot as he sang about the Edmund Fitzgerald. But this wreck, the Sweepstakes, has been visited by more people than perhaps any other Great Lakes Shipwreck. It lies in only 20 feet of water in Big Tub Harbor. Today, people snorkel…