Which frequencies are designated for "On-scene" communications in the Global Maritime Distress and Safety System?

The frequencies designated for "On-scene" communications within the Global Maritime Distress and Safety System (GMDSS) play a crucial role in ensuring effective coordination and response during maritime emergencies. The correct answer identifies VHF Channel 16 and SITOR (NBDP) on 2174.5 kHz as the primary means for these communications.

VHF Channel 16 is widely recognized as the international distress and calling frequency, primarily utilized for distress calls and emergency messages. Its importance in on-scene communications stems from the fact that it is monitored by all vessel operators and is the first line of coordination during a maritime distress situation. This allows for rapid establishment of communication between vessels in distress and those able to assist.

SITOR (NBDP) on 2174.5 kHz is also integral for on-scene operations, as it is used for sending different types of messages, particularly for safety and operational communications. The frequency and mode are designed for reliable communication over maritime radio, supporting the coordination of search and rescue operations.

The other choices mention frequencies that are either not specifically dedicated to "on-scene" communications or are used for other purposes in the context of GMDSS. While they may have their uses in communications,