People have been fighting over Lake Champlain as long as there have been personal flotation devices. The waterway’s strategic value is evidenced by the dozens of shipwrecks on the bottom. The Lake Champlain Maritime Museum has been discovering, researching and protecting those rusty relics, and the result is the Lake Champlain Underwater Historic Preserve, a gallery of sunken ships accessible to divers. But there’s plenty to look at on land, too. The dry museum chronicles the maritime history of the area through exhibits, boat-building demonstrations, lectures and festivals. Re-enactors take over the place for two days at the end of August. The “Rabble in Arms” Living History Weekend includes a re-launch of the 1776 replica gunboat Philadelphia II.