How is a MSI (Maritime Safety Information) broadcast received by an Inmarsat-C SES engaged in communications?

In the context of receiving Maritime Safety Information (MSI) broadcasts via Inmarsat-C Ship Earth Stations (SES), option C highlights an important feature of the MSI system. When a "vital" MSI message is transmitted, the system is designed to ensure that essential safety information is not lost. This is accomplished by the protocol that includes repeated broadcasts of crucial messages.

MSIs are critical because they can include time-sensitive information about navigational hazards, weather conditions, and other safety-related updates. Recognizing their importance, the Inmarsat system will repeat these vital messages to mitigate the risk of missing them during transmission. As a result, even if a vessel misses the initial broadcast, there will be subsequent broadcasts that allow for the critical information to be received eventually.

The other options do not accurately describe the functioning of MSI broadcasts within the Inmarsat-C system. The broadcast message being missed and requiring a retransmission would not apply to vital messages that are designed to be repeated. Storing messages in EGC memory is part of the system, but it does not specifically pertain to the reassurance that vital messages will be retransmitted. Similarly, while requesting retransmission can be useful for non-vital messages, the core design of the system prioritizes