IT SENDS A RADIO SIGNAL FROM THE BOTTOM OF THE SHIP TO THE SEA-BED, FROM WHICH IT IS REFLECTED.
For safe navigation, the following equipments are available:
a. Magnetic and Gyro compass, GPS receivers: for position or location finding
b. Echo sounders: for finding the depth below the ship
c. Wind Speed and Direction instruments
d. Electric or Air Siren
e. Speed log: to measure the speed of the ship
f. Navigational radarsg. Signaling projectors