gas usage

I have a 1985 sea ray boat with a 350 chev engine. What I want to know is, has anyone try a four bladed prop on their boat of the size. I want to know if they get better gas mileage with the four blade prop. thank you john:smt038

2005 300 Sundancer with twin 5.0's We are new at owning a searay and do not understand why the fuel consumption is big. We have several friends that own the same boat and some with bigger engines and do not go thru the fuel we do........and drive more then we do. We need some help and...