Swimming at this beach in Acadia National Park in Bar Harbor, Maine, calls for a little more bravado than elsewhere on the New England coast. The Labrador Current just brushes Mount Desert Island, bringing some bracing waters from the Canadian Arctic. The ocean temperature rarely rises above 55 degrees, and thats measured in Bar Harbor. Its always colder at Sand Beach. Since the park entrance fee is good for seven days, you can wade in a little more each day to reach full immersion while the pass is still valid. Kids and a few other brave souls seem to enjoy staying in the water until their lips turn blue. 207-288-3338, www.nps.gov/acad. Entrance fees through Oct. 31 $20 per vehicle and passengers ($10 after Columbus Day), $5 per individual for seven days. Hulls Cove Visitor Center open daily 8 a.m.-6 p.m. through August, until 5 in September, and 4:30 in October.