How To Make A Propeller For A Mini Boat I Have A Science Project Where I Have To Buid A Mini Boat Out Of Pop Bottles And Styrofoam And Stuff...?

I have a science project where I have to buid a mini boat out of pop bottles and styrofoam and stuff...? - how to make a propeller for a mini boat

I have a science project where I build a mini-bottles of soft drinks and boat foam polystyrene and other things that you can help me to build a road to a propeller or something that may help him to move faster? The materials I have are everyday objects and other things, my son, and so on. But please help me understand how to build them. :) Thanks