Definitely take a boat tour while you're in Portland, Maine! It was one of my favorite parts about my trip. There are several different boat companies and tours to choose from, and they usually last between 1.5-3 hours. The tour I took showed us all of the different light houses around Portland, and told us the story behind each one. Once you're out in the open water, the next piece of land to the east Portugal- 3,000 miles away! Also, be prepared because it does get super windy on the boats. So make sure to bring a jacket and your camera to capture the gorgeous scenery.