The Beal & Bunker ferry, leaving from Northeast Harbor, passes right by this lighthouse, giving you a free photo opportunity as you travel to Great or Little Cranberry Island.
You can't visit Bear Island because it is all private land.
The light is no longer operational, and the light keeper's cottage is leased by the government to a private individual.
History of the Bear Island Lighthouse
Bar Harbor Times article about the Bear Island Lighthouse
commercial page featuring the lighthouse
Most of Baker Island is part of Acadia National Park. A narated tour boat out of Northeast Harbor passes by the island, but to actually land there you have to hire a private boat. Landing is difficult, as there's no dock.
history of the Baker Island Lighthouse
The Baker Island Light page of the National Park Service