Mercury - Quicksilver Black Diamond Bravo Two Propeller 17.75" Diameter x 21" Pitch Left-Hand Rotation 3 Blades Aluminum Black Finish QA1947R. Overview. Every captain knows the quiet confidence that comes when your boat moves exactly how you expect - steady, strong, and unshakable. That kind of performance comes from the right prop pushing behind you, and the Quicksilver Black Diamond Bravo Two delivers just that. Designed for Bravo Two drives and big-bodied boats that need real torque, this pro