Which sensor has the highest heading priority?

• A. NAVSSI
• B. WSN-7
• C. DFGMC
• D. GPS

Answer: (B)

Heading data in ship navigation uses a priority order so the most stable reference drives the display and the vessel’s control systems. The gyrocompass provides a continuous, true heading that is largely independent of magnetic interference, vessel speed, or satellite geometry. Because of this reliability and stability, it is treated as the primary heading source for the bridge and related systems.

The WSN-7 is a gyrocompass—the sensor that delivers this top-level heading reference. Its output remains consistent even in environments with heavy magnetic disturbances or iron, which can skew magnetic compasses. That makes it the best single source for heading.

Magnetic compasses, like the digital fluxgate type, are valuable for redundancy and backup, but their readings can be distorted by nearby metal, electrical equipment, and other magnetic fields. GPS can provide course over ground, but its heading information depends on movement and can be unreliable when stationary or in complex maneuvers; it is typically used to augment rather than define heading. NAVSSI is the interface that distributes sensor data, not a heading source itself.

So, the sensor with the highest heading priority is the gyrocompass (WSN-7).