Small passenger vessels that sail 20 to 150 nautical miles from the nearest land must have what additional equipment?

For small passenger vessels that operate between 20 to 150 nautical miles from the nearest land, having an MF-HF SSB (Medium Frequency - High Frequency Single Sideband) transceiver is essential for ensuring reliable communication. This range from land poses unique challenges such as potential loss of sight of land and increased risk during emergencies.

The MF-HF SSB transceiver allows vessels to communicate over long distances, which is crucial for both safety and coordination with maritime services. It enables access to emergency channels and can be used to reach coast stations that may be miles away, helping ensure that vessels can send distress signals and receive assistance if needed.

In contrast, the other options, such as Inmarsat terminals and the aircraft transceiver, while useful for various forms of communication, do not fulfill the specific regulatory requirement for small passenger vessels operating in the specified maritime distance. In particular, Inmarsat systems generally provide satellite-based communications rather than the direct maritime communications often needed for vessels. The aircraft transceiver operates primarily on frequencies associated with aviation, which are not the standard for maritime applications. Thus, the MF-HF SSB transceiver is the appropriate equipment for ensuring compliance and safety in maritime operations within this range.