A canoe make the most sense but I think these would be more practical (until you ran out of gas)

http://www.argoatv.com/recreational/recdetailvehicles.aspx?x=Eyd6xjM6%2fFP8uuK%2bZYevYg%3d%3d

A few years ago parts of Edmonton flooded pretty badly. I was working at a dealership that sold these and the new models were parked outside in a coral waiting for PDI. They were so boyant we had to hop in one and ride out into the yard to lasso and anchor them before they floated out into traffic!