GMDSS: Element 7

1. A Polling, enhanced group call, and one-way position and data reporting via satellite.
2. B FM voice communications via satellite.
3. C Two-way messaging and data communications on a store-and-forward basis.
4. D Polling, enhanced group call, one-way position and data reporting via satellite, two-way messaging and data communications on a store-and-forward basis.

Tip: press A-D to answer