The AMOS-AirProp is an electric, computer controlled, rotatable air propeller that is used for propulsion and steering of the AMOS (Aquatic Mini Observation System) robot from In Nature Robotics Ltd.
It consists of a 10 inch propeller blade that is mounted to a 2200 kv brushless motor, which is in turn mounted to a vertical post whose yaw direction is controlled by a waterproof servo motor.
An Electronic Speed Control (ESC) board is also included for controlling the speed of the propeller motor. The ESC and the servo motor are both controlled using pulse width modulated (PWM) signals from a host processor such as the Raspberry Pi (TM). See https://www.innaturerobotics.com/support for product manual and example source code.