Propulsion systems for boats, including, power boats, and components and fittings therefor, such as shaft, propeller, stator vane, nozzle, rudder and intake grate; engines and motors in this class, including, outboard and other marine engines and motors, propulsion engines for boats, marine propulsion engines, marine transmissions, marine mechanisms (control mechanisms for machines, engines or motors and transmission and propulsion mechanisms for boats), marine shafts.;