Lying half a mile south of Castine and guarding the entrance to Castine Harbor, the island has a long, rich history. During the Revolutionary War the American vessel Hazard engaged the British sloop of war Nautilus off the island's shores and the island has been known as Nautilus ever since. It was captured from the British on July 26th 1779 by men of the Continental Marines commanded by Paul Revere as part of action undertaken by the Penobscot Expedition.
The island features in the opening of the famous poem "Skunk Hour" by Robert Lowell: "Nautilus Island's hermit heiress still lives through winter in her Spartan cottage; her sheep still graze above the sea. ... Thirsting for the hierarchic privacy of Queen Victoria's century, she buys up all the eyesores facing her shore, and lets them fall."