Mercury - Quicksilver Black Diamond Bravo Two Propeller 17.75" Diameter x 21" Pitch Right-Hand Rotation 3 Blades Aluminum Black Finish QA1946R. Overview. There's something powerful about the way a big boat moves when it's got the right prop behind it - steady, confident, and unhurried. The Quicksilver Black Diamond Bravo Two Propeller is built for that kind of control. Designed to handle serious torque, it pushes heavy hulls with a smooth, deliberate strength that you can feel from the throttle