How do submarines use gyrocompasses for navigation?

Submarines utilize the gyrocompass as a primary navigational device because it is immune to the magnetic interferences—such as steel structures and electric circuits—that would otherwise disrupt a standard magnetic compass.1

By employing a continuously driven gyroscope, the instrument seeks an equilibrium direction based on the force of gravity and the rotation of the Earth, allowing it to accurately indicate true geographic north rather than magnetic north. This capability is essential for the precise navigation of submarines, where it also serves as an azimuth reference for torpedo control.12

To maintain accuracy while the submarine is in motion, the gyrocompass is designed to compensate for vehicle accelerations and the apparent rotation of the meridian caused by the vessel's speed over the Earth's surface. In modern naval operations, these systems are often integrated into broader inertial guidance systems, which use gyroscopes and accelerometers to continuously monitor the submarine's position, velocity, and acceleration without needing external communication.34