What is the recommended first action when navigation data is suspected to be compromised by a cyberattack?

• A. Switch to backup navigation sources.
• B. Ignore until directed by higher authority.
• C. Shutting down all navigation systems indefinitely.
• D. Reducing surveillance to save energy.

Answer: (A)

When navigation data may have been tampered with, the immediate goal is to maintain safe and accurate positioning using trusted, independent sources. Switching to backup navigation sources is the best first action because it restores reliable situational awareness while the integrity of the primary data is being assessed. This preserves the ability to determine course, speed, and position and allows continued safe navigation without relying on potentially compromised information.

Ignoring the alert leaves you exposed to incorrect data and increases the risk of collision or grounding. Shutting down navigation systems indefinitely removes essential ability to determine position and can leave the vessel adrift or unable to navigate safely. Reducing surveillance to save energy degrades safety and reduces the ability to detect threats or hazards, making it an inappropriate first step.