If you take a closer look at what yacht owners do and talk about you would notice that they always discuss some kind of optimization. If it is about sailing, they would discuss sails, keels, ballast or tillers for hours. If it is about power boats the discussions would be about subjects such as engines, displacement, fuel consumption…
What these two groups have in common is the propeller. They both want to optimize the speed by choosing a ‘more efficient’ propeller. One group of powerboat owners search for those which produce more power while the other ones are looking for those which produce lower sailing drag. In both cases the speed would improve, regardless of the propulsion system.
Italian company MAX PROP (former Bianchi Srl., founded in 1975.) has solved many problems regarding owners’ doubts about high sailing drag, maneuverability and engine performances. They produce MAX PROP feathering propellers which blades take the pitch chosen during the assembling in a totally automatic way. The wings take the identical angle both in their forward and reverse position, gaining the same level of performance either when driving or maneuvering in the port.
For racing sailboats MAX PROP recommends their Classic 2 bladed propeller which has the lowest sailing drag of any other feathering propeller at the market. For cruiser sailing boats there are Easy 3 or Easy 4 bladed propellers. They also have very low sailing drag with externally adjustable pitch.
These propellers are very easy to install so it could be done by a diver. Powerboat owners could be interested in Whisper 5 bladed propellers which offer extra low drag, efficient power, outstanding reverse performance, externally adjustable pitch and one piece installation. All propellers, regardless of whether they are on sailing boats or powerboats, need to be resistant to marine corrosion, dynamic and static stress and to wearing.
Therefore, a high resistance bronze was chosen as a material which includes all mentioned features along with good strength and toughness which gained its resistance to impacts. The sizes and assembly details are available at MAX PROP web page while there is internet shopping through E-bay as well.
I wish you a calm sea, a fine wind and a strong mast!