Poor man raft. help!

me and my friends want to make a cheap joy ride raft. as long as in runs once, its good enough. we want to take 4 people down an easygoing river. maybe that is too much to ask for a budget of twenty dollars but if we be inovative we could probly pull it off. we do have a little lumber. thanks!

 

old truck inner tubes (free from tyre reapir place) , tied to the bits of wood you have with some strong rope from the local supermarket, covered in a cheap tarpaulin from the local camping place - pick a nice day and have a great time (oh - you *do* have lifejackets ... dont you ?)

 

thanks you!