🔍 Key Concepts

• GMDSS DSC call setup for non‑distress traffic • Difference between MMSI and SELCAL and when each is used • Use of F1B (NBDP/Telex) emissions and choosing the correct priority level

💭 Think About

• Is “important company business” considered distress, urgency, safety, or routine under GMDSS priorities? • In a DSC call to another ship, whose identifying number should be entered so that THEIR radio responds? • For setting up a Telex (NBDP) contact, which identifier does the DSC controller actually require: MMSI or SELCAL?

✅ Before You Answer

• Verify the correct priority category for commercial/administrative traffic under GMDSS (not involving safety of life). • Confirm that DSC calls are addressed using an MMSI (Maritime Mobile Service Identity), not a SELCAL, and whose MMSI is used. • Check that the emission designator F1B corresponds to NBDP/Telex on an appropriate alternate frequency.