I need to know the size of my propeller so I can start looking for a spare one. Unfortunately I am new to this whole boating thing and have not gotten the hang on this propeller sizing, WOT, min rpms max rpms... My boat is a 1968 Mark Twain with what I think is 120 hp MerCruiser in it. The current propeller on it reads like this - u205 T21-441 t898. Your help would be greatly appreciated.
