See: [[#pitch_effective|Pitch, effective]]
===== Efficiency, mechanical =====
The r... I</sub> is the indicated power (which see).
===== Efficiency, propeller, behind hull =====
(//η//<sub>B</sub>)... elative rotative efficiencies respectively.
===== Efficiency, propeller, open water =====
(//η//<sub>O</sub>)[... r and //n// the rate of propeller rotation.
===== Efficiency, quasi-propulsive or quasi-propulsive coefficient