What is the key function of a second radar on larger vessels?

The key function of a second radar on larger vessels is to provide redundant navigation. Redundancy in this context means having a backup system in place to ensure that navigation can continue safely and accurately even if the primary radar system fails. Large vessels often operate in busy maritime environments where precise navigation is critical for avoiding collisions and ensuring safe passage.

Having a secondary radar system enhances the reliability of navigational information, allowing the crew to cross-check data and maintain situational awareness. This is especially important in adverse conditions or during complex maneuvers, where relying on a single system could pose significant risks.

While the other functions listed, such as emergency navigation, speed verification, and weather assessment, are important aspects of marine operations, the primary role of a second radar is to serve as a redundancy to ensure that navigational abilities are maintained without interruption.