You’ll have to wake up pretty early in the morning to secure passage to the small scrap of Acadia National Park  located on Isle Au Haut in Penobscot Bay . In the summer even that won’t help you. Only 48 day-trippers are allowed daily on the island—and spots are often booked weeks in advance. If you can get aboard, you’ll find one of the most rugged and impossibly gorgeous of all the islands in Penobscot Bay.
While it is right next door to Deer Isle  and Vinalhaven , Isle Au Haut has remained remote and sparsely populated, mainly because of the parkland that covers its southern half. It gained some notoriety of late because of the book written by captain Linda Greenlaw (of The Perfect Storm fame) about her years growing up in a lobster village here, but even that has barely punctured its serenity.
About the only thing to do here is hike in the pristine wilderness. The mile-long trail up Duck Harbor Mountain is a rigorous climb to a spectacular vista, while the Western Head and Cliff Trails offer miles of ocean scenery.
You may feel like you’ve walked into a dream when you stumble across the Black Dinah Café (1 Moore’s Harbor Rd., 207/335-5010, www.blackdinahchocolatiers.com , May–Sept.) at the end of a wooded trail at the base of an island mountain. You’ll know you are dreaming when you bite into the decadent chocolates made on-site by Black Dinah Chocolatiers. The only way to prove it is real is to buy a bag of lavender dark-chocolate truffles to take home…The café also serves pastries from scratch using local and organic flours, eggs, and cream.
One of the more dramatic places to stay in Maine  or anywhere else has long been The Keeper’s House (Lighthouse Pt., 207/367-2261, www.keepershouse.com ), a five-room inn attached by causeway to the gorgeous Robinson’s Point Light. While the house has suspended inn operations for the time-being, it still rents out “The Woodshed” ($2000/week), a former storage shed that has been transformed into a snug and cozy cottage with renovated kitchen, bath, and music system. The house is completely off-the-grid, run by windmill and solar power. Water comes from the ocean by way of a desalinizer.
For an even more rustic experience, Acadia National Park  operates the Duck Harbor Campground (207/288-3338, www.nps.gov/acad , mid-May–mid-Oct.), a spartan campground with five lean-to shelters. Be sure to call ahead far in advance to reserve a spot; the park requires campers to fill-out a reservation request ahead of time. When your reservation is confirmed, you are issued a “special use permit” for $25, which you must bring to the island with you. There is no additional charge for the campground. Also, be aware that the mailboat only travels to Duck Harbor from mid-June to late September. Outside of that time period, you’ll have to schlep your gear from the Town Landing.
Passage to Isle Au Haut is through Isle Au Haut Boat Company (Sea Breeze Ave., Stonington, 207/367-5193 or 207/367-6516, www.isleauhaut.com ), which operates a mailboat ferry to the island on a first-come, first-serve basis. During summer months, five ferries leave daily Monday through Saturday, and two on Sunday. During the rest of the year, trips shrink to three a day Monday through Saturday. Round-trip fares in-season are $35 adults, $19 children, and include a free return-trip on the same weekend.
For an extra $20, you can reserve a bicycle ahead to be ready for when you arrive. The ferry arrives in Isle Au Haut at the town docks; during the summer it continues on to the National Park at Duck Harbor. Be advised, however, that only 48 daytrippers are allowed into the park daily (not including campers). Arrive early at the docks in Stonington .