Your outboard needs a propeller—maybe two if you are smart and carry a spare. There are literally dozens of prop options for most outboards, so start here. Outboard props come in three flavors: ...

Every motorboat owner has a tale of hitting a submerged obstacle or boat ramp and damaging a propeller. Typically metal, it must be removed and taken to a prop repair shop, then sandblasted, bent, ...

Years after the space race, propeller design remained a sea-trial-and-error endeavor: haul, tweak the props, relaunch, sea-trial, repeat. Finally, the U.S. Navy paid ...