Final answer:
The device that indicates the rate of turn of a vessel is a Rate of Turn Indicator. It measures how quickly the ship is turning in degrees per minute. The other options listed are related to navigation and position, but not the rate of turn.
Step-by-step explanation:
An electronic or electric device that indicates the rate of turn of a vessel is known as a Rate of Turn Indicator. This device measures how quickly a ship is turning, typically indicated in degrees per minute. The correct answer from the choices given is (d) Rate of Turn Indicator.
The options that are not correct include (a) Echo sounder, which utilizes sonar technology to measure the depth of the ocean by sending sound waves that reflect off the seabed. The sound waves' travel time helps determine the distance. An echo sounder is not related to indicating the rate of turn. (b) Rudder indicator shows the position of the ship's rudder but doesn't indicate the rate at which the vessel is turning. (c) Gyrocompass repeater displays the heading of the ship based on the gyrocompass, which maintains a fixed position relative to true north, but does not provide turn rates.