Why on a ship?!

Almost all of Act III takes place on board of the ship to England. The boat is used to reflect the experience of living in a universe that is beyond our control. Rosencrantz and Guildenstern originally respondle positively to being on the boat, because they like not having any responsibilities and being able to "float through life". They believe this is freeing because they can no longer worry about making the wrong decisions, but instead just go along with wherever life takes them. Guildenstern then realizes that getting on the boat was a mistake because when they gave up all their freedom they also lost all control over their lives. this is so symbolic and right on with the entire play, and the characters of Rosencrantz and Guildenstern.