Neel help on water propulsion device

Im currently doing a project involving water propulsion. I've thought about using turbine and it will cost a lot.

Any idea on what should i use would be perfect. I prefer doing a small project first before moving into a bigger one.

Your help is very appreciated. Thank you.

Define “small” and “bigger”.

Im currently doing a project involving water propulsion.

Like moving a boat? It's hard to beat a tried-and-true propeller. ;)

Define also "a lot"