Below is a link to a recorded presentation made by Bombardier Recreational Products that explains the basics of propeller operation. I highly recommend watching this presentation. The presentation contains numerous animated illustrations that show the interaction of a propeller with the water stream that demonstrate subtle elements of the operation of a propeller. Although the initial minutes of the presentation go over basics, the later portions provide rather interesting explanations of subtleties of propeller operation.
Propeller Selection
https://www.youtube.com/watch?v=xbDsTBhL4Cs