Set sail on a 4-masted schooner, the Margaret Todd, and take in fabulous views of the Porcupine Islands, Frenchman Bay and Acadia National Park. Admission is rather pricey, but the experience is amazing. The cruise that I went on was narrated by a park ranger who told us about the history of Mount Desert Island and the founding of Acadia National Park. He also pointed out the area wildlife. Bring binoculars! The seals and birds are fun to watch, but are quite far away.