We were staying near bar harbor, unfortunately the gov't shutdown closed the park and left us looking for some alternate activities. We took the lighthouse tour which was great. We got to see a few lighthouses, and see the park from the sea.
Dress warm! I wore a few layers, a fleece, and a winter coat.
Bathrooms were available on the boat, though we didn't use them. Refreshments were also available for purchase, but we also didn't use this option. We brought our own binoculars, but they could be rented from the refreshments area. We didn't take any dramamine, but we were fine without.
I wish we'd gotten in line earlier for a better spot, but the boat always turned so both sides of the boat could see each lighthouse. But I think it would have been a bit more enjoyable from the front of the boat.