You can take the "Banana Boat" from the UK to the Caribbean. It even has a shuffle board on the deck. The cargo ship delivers goods to Caribbean Islands and picks up bananas and other fruits to deliver home. They have a few extra cabins that are availble for travelers.
We watched a travel documentary about it on PBS. The passengers thought it was a great and cheap(er) way to travel to the Carribean. Granted, there was little entertainment outside of singing sea shanties with the crew and playing shuffleboard, but it looked like fun.