There are other boats that sail around the world and in my understanding, all the others are just very common tourist ones. In Peace Boat there is a huge amount of different activities where everybody can participate, including lectures and workshops related to peace awareness and similar topics, participating in volunteer work to help running the everyday life on the boat, and participating in exchange programs in the cities where the boat stops.
Also, most of the daily activities are actually filled by the other participant, as anybody is encouraged to teach or share any special knowledge or skills that they have. Then, totally depending on the participants and what is shared, every voyage end up being very different from each other. I think all this make it a very unique program.