Kevin: I was looking in the back of one magazzine and I found advertisement of CDI props, they are made of Urethane and claim to vary the pitch according to engine speed, also they claim that reverse is enhanced by a more increased pitch. what do you think about them? shall I give them a try? they look attractive to me 'cause i have to back my boat into my slip a little ways. Thanks Ed Tamara S/V Mastconfusion