What is the primary purpose of frequency hopping in maritime communications?

• A. Increase security by making interception harder
• B. Weather adaptation
• C. Increase noise
• D. Decrease bandwidth

Answer: (A)

Frequency hopping is a spread-spectrum technique that quickly changes the carrier frequency across a predefined set according to a pseudo-random sequence shared by transmitter and receiver. In maritime communications, this makes the signal much harder to intercept or jam because an adversary would have to monitor and jam across many frequencies in rapid succession, rather than a single channel. The receiver must stay synchronized to the hopping pattern to decode the message, which is why this approach significantly complicates eavesdropping and interception. While it also provides resilience against narrowband interference, its main purpose is to enhance security by reducing the likelihood that the message can be intercepted or disrupted on any one frequency.