Fathometer is used to measure
The measurement is used to gauge an ocean’s depth. Option (3)
A fathometer is a depth meter that uses sound waves to measure the depth of the water.
A device is used for measuring the depth of the water by the length of time needed for a sound wave to travel from bottom to surface for its echo to return. It is also employed to measure the rising and falling of the tides at offshore locations.
A Fathometer is a gadget used to measure the depths of oceans. The Fathometer, often referred to as 312 fathometers, was developed through the Boston submarine signal company in 1925. It made it easier to measure the depth of water as it gave more precise information than other sounding methods.