🔍 Key Concepts

• GMDSS Telex (NBDP) direct dialing format from a ship station • Difference between country code and Ocean Area Code in maritime communications • Use of international access prefixes (0 vs 00) and the end-of-address symbol (+) in Inmarsat dialing procedures

💭 Think About

• First decide whether a direct shore TELEX call should use a country code or an Ocean Area Code when dialing a land-based TELEX terminal. • Think about what prefix is normally used on Inmarsat when calling a terrestrial telephone/telex network (compare with how you dial an international phone call). • Look at where the + sign belongs in GMDSS telex addressing: does it replace part of the number, or is it used to mark the end of the address?

✅ Before You Answer

• Verify in your GMDSS manual the exact DIRTLX command syntax for a shore-based TELEX terminal (not ship-to-ship). • Confirm whether 00 or 0 is the standard international access code used before a country code from an Inmarsat terminal. • Check which options correctly place the + at the end of the sequence to indicate end of address.