Mercury - Quicksilver Black Diamond 3-Blade Aluminum Propeller 7.8" Diameter x 8" Pitch Right-Hand Rotation 3-Blade Aluminum High-Gloss Phantom Black Finish QA3184R. Overview. Every boater knows that feeling when a prop just fits when it grips the water cleanly, accelerates without hesitation, and makes the boat feel perfectly tuned. The Quicksilver Black Diamond 7.8" x 8" Pitch Propeller (QA3184R) captures that magic in a small but mighty package. Smooth, balanced, and easy to handle, it's the