🔍 Key Concepts

• SITOR (NBDP) and what type of service it provides (HF/MF telex-like data) • How ship stations are uniquely identified in GMDSS (Global Maritime Distress and Safety System) • The relationship (if any) between MMSI numbers and selective calling numbers (SELCAL) for digital modes

💭 Think About

• For SITOR/NBDP ship-to-shore communication, what kind of identification number must be recognized internationally and be unique to that ship? • Look at which options mention a number format that is standard in multiple GMDSS digital systems (DSC, NBDP, etc.). Which answers mention numbers that are specific only to satellite equipment types? • Does SITOR/NBDP use the same identification concept as DSC/MMSI, or does it rely on a completely separate, unrelated number scheme?

✅ Before You Answer

• Check which choice links the SELCAL number to the MMSI (Maritime Mobile Service Identity) structure used in GMDSS • Verify which choices are tied to specific Inmarsat terminals (like F77 or FleetBroadband) rather than to the general ship station identity • Make sure the format you choose can be used for HF/MF telex-style data and is not limited to just satellite voice/data services