GMDSS: Element 7

1. A To provide an additional number which may be dedicated to computers, fax, etc.
2. B To provide an alternate number which may be called if a busy signal is received by the calling party.
3. C To provide an additional speech path, which may be used to communicate while the first channel is engaged in active communications.
4. D To provide for an emergency working frequency.

Tip: press A-D to answer