GMDSS

Question 1

What is GMDSS?

Answer 1

Global Maritime Distress and Safety System → international comms & safety procedures.

Question 2

Name the 6 functions of GMDSS.

Answer 2

1. Alerting (inc. position). 2. SAR coordination. 3. Locating (homing). 4. Maritime safety information (MSI). 5. General & bridge-to-bridge comms.

Question 3

Do requirements depend on tonnage or sea area?

Answer 3

Requirements depend on sea area (A1–A4), not tonnage.

Question 4

What vessels are exempt from GMDSS requirements?

Answer 4

Vessels <300 GT on international voyages.

Question 5

Define sea area A1.

Answer 5

VHF DSC coast station coverage (~20–30 NM).

Question 6

Define sea area A2.

Answer 6

Outside A1, within MF DSC (~100 NM).

Question 7

Define sea area A3.

Answer 7

Outside A1 & A2, within INMARSAT coverage (~70°N–70°S).

Question 8

Define sea area A4.

Answer 8

Polar regions (outside A1–A3).

Question 9

What is the minimum GMDSS equipment for all ships?

Answer 9

VHF DSC (Ch 70), R/T (Ch 16, 13, 6), SARTs, survival craft VHFs, NAVTEX, Inmarsat EGC receiver.

Question 10

How many SARTs are required for a 400 GT ship?

Answer 10

1 SART.

Question 11

How many portable VHFs are required for vessels ≥500 GT?

Answer 11

3 portable VHFs.

Question 12

When is NAVTEX required?

Answer 12

Where available.

Question 13

When is an Inmarsat EGC receiver required?

Answer 13

Where NAVTEX is not available.

Question 14

What are the 3 sources of power for GMDSS?

Answer 14

1. Ship’s mains. 2. Emergency generator. 3. Radio battery.

Question 15

How long must radio batteries last with emergency generator? Without emergency generator?

Answer 15

1 hour with EG, 6 hours without EG.

Question 16

How is battery changeover achieved?

Answer 16

Auto changeover → ‘no break’.

Question 17

What are the 3 approved maintenance methods for GMDSS?

Answer 17

1. At-sea maintenance. 2. Duplication of equipment. 3. Shore-based maintenance.

Question 18

How many methods must A3/A4 ships comply with?

Answer 18

≥2 methods.

Question 19

What does ‘MAYDAY’ mean?

Answer 19

Grave & imminent danger, immediate assistance required.

Question 20

What does ‘PAN-PAN’ mean?

Answer 20

Urgency (safety of vessel/person).

Question 21

What does ‘SECURITE’ mean?

Answer 21

Safety (navigational/weather warnings).

Question 22

What do you do if you hear a MAYDAY in A1?

Answer 22

Wait for coast station first, then follow distress handling procedure.

Question 23

What do you do if you hear a MAYDAY mid-Atlantic?

Answer 23

Acknowledge, get info (position, ID, POB, nature of distress, assistance required), consider relay, proceed to assist, alert CRS, prep SAR gear.

Question 24

What do you do if you hear a distress on HF?

Answer 24

Do not acknowledge; if no coast acknowledgment, relay to shore.

Question 25

What is a Mayday Relay, and how is it sent?

Answer 25

RT voice only (not DSC); last resort via coast station.

Question 26

If you see a red flare, what do you do?

Answer 26

Treat as a distress signal and respond accordingly.

Question 27

What is NAVTEX, and what frequency?

Answer 27

NAVTEX is an automated MSI broadcast at 518 kHz.

Question 28

Which NAVTEX messages cannot be switched off?

Answer 28

SAR, nav warnings, MSI.

Question 29

How often must battery voltage and specific gravity be checked?

Answer 29

Daily for voltage; monthly for specific gravity.

Question 30

What precautions should be taken when handling lead-acid batteries?

Answer 30

Ventilate during charging (hydrogen risk) and top up with distilled water only.

Question 31

May day script

Answer 31