magnetic compass
a rudder
Rudder
A device which operates(or function) only in one direction is called unidirectional (or unipolar) device
Sextant
The Compass-
Ships are steered by a device called a rudder, which is operated from the helm.
Gravity is the biggest determining factor of the direction of motion of a vessel in orbit, and the rocket's engines are used to change the shape of that orbit.
marine chronometer.
Sandglass or ampoletta
propeller
The marine chronometer is used to tell time on a ship. It was created in the 18th century and is very precise and accurate.
The device is called a windlass.
The device is called a marine chronometer.
Wind vanes or wind socks.