When most people think of Vermont "scuba diver's paradise" doesn't exactly spring to mind. But because of its cold temperatures, Lake Champlain holds one of the best collections of shipwrecks in the United States. Vermont was one of the first states to create a public underwater historic preserve, with seven shipwreck sites currently open to the public. But to see them up close, you have to dive. We spent some time recently with a class at the Waterfront Diving Center in Burlington to get a first-hand look at what it takes to scuba dive.