Ten miles out to sea, Smuttynose Island, in the Isles of Shoals, is a kind of time machine. Native Americans hunted here more than 6,000 years ago. In the dawning days of the American colonies, hundreds of European fishermen salted and dried their prized Atlantic cod. There was an ancient tavern when the Isles of Shoals were an important staging point for New England trade. Today, only two buildings survive on this flat, primitive...