What would be vital to a GMDSS SAR situation in polar regions?

In a GMDSS Search and Rescue (SAR) situation in polar regions, utilizing COSPAS/SARSAT satellites to receive distress alerts is crucial. The COSPAS/SARSAT system is specifically designed for search and rescue operations and provides global coverage, including the challenging environments found in polar areas. It allows for the detection and location of emergency beacons activated by vessels or individuals in distress, which is vital for initiating an effective rescue operation.

HF (High Frequency) voice communication becomes essential for follow-on communication during a SAR operation. HF voice is capable of long-range communication, which is particularly beneficial in the vast and remote polar regions where other means of communication may be limited due to terrain, distance, or adverse weather conditions. This combination of satellite detection for alerts and voice communication for coordination significantly enhances the effectiveness of rescue efforts in such extreme environments.

The other choices involve systems that may not provide the same level of support in SAR operations within polar regions, making them less advantageous in these specific circumstances.