What can I make a boat out of?

we are doing a project in school about movers and shakers in history and the person i am researching is Julius Caesar so for my visual i wanted to do something about when he went to rhodes and was captured by pirates. so what i wanted to make a boat and make kind of like a little scene going on, on the boat but the problem is that i have no idea what kind of material i should make it out of or how to make the actual boat the rest i'll make out of clay and wood and stuff but i just need to figure out how to make a boat. i don't need it to be huge but something i could carry because it's just for a school project.thanks