(coloured pink), A'2 (green) and A3 (blue). The map does not extend
beyond 70° North, so no A4 area in this map.
GMDSS Land-based Infrastructure and Ship's Main GMDSS Equipment
The G MDSS infrastructure for Distress and Safety communications
consists of a range of land-based facilities, with the MRCC as the hub of
distress, urgency and safety communications (see figure 1.4).
A range of systems is available to let ships at sea connect, directly
or indirectly, to the MRCC. The GMDSS infrastructure provides for
the full range of maritime distress, urgency, safety and routine
communications between ship and shore, and ship-to-ship, but - as
mentioned earlier - some 'other' communications are now being carried
out on non-GMDSS systems (covered in later chapters).
Questions from Chapter
1 Which of the following describes Sea Area A3?
(a) Within radiotelephone coverage of a VHF DSC coast station.
(b) Within coverage of the Inmarsat satellite system.
(c) Within radiotelephone range of an MF DSC coast station.2 Which of the following systems use satellites to relay information?
(a) SSB Radio with digital selective calling.
(b) Cospas-Sarsat EPIRB.
(c) Search and Rescue Transponder (SART).
(d) Inmarsat-C transceiver.
3 Put the following four 'Priorities of Communication' in order, starting
with the highest priority first:
(a) Routine.
(b) Distress.
(c) Safety.
(d) Urgency.
Answers from Chapter 1
1 (b)
2 (b) and (d) both use satellites
3 Distress, Urgency, Safety and Routine.
10 THE NAUTICAL INSTITUTE