Crossing takes an hour and a half. The schedule varies seasonally. From September 5 through November 30, the ferry makes four daily trips Monday through Friday and three on Saturdays and Sundays. Enjoy nature and get to know the people, mostly. The island offers some spectacular scenery, including rock formations, spruce forests, seaside cliffs, and wild beaches perfect for viewing the sunset.
Summer is the peak tourist season.
Birders also enjoy fall migration time and even winter seabirding. Many lodgings shut down after summer, but several remain open year-round. Most of the inns, cottages, motels, and campgrounds are on the ocean, or at least within sight of it. It has just about everything you'd need to know to visit Grand Manan, including lists of accommodations. You can also buy it at the Grand Manan Museum gift shop.