Hi! I do not have an airboat - I am building one - I have a question if anyone can help me - why cut down the prop and how much would you cut down on 20/8? Any more helpful hints would be appreciated.

cuttin down props is the worst thing to do on rc boats to many vibrations and the section closest to the hub does all the work not the tips they are pretty cheap any ways better of buying an assortment of them i did.