What are the communication requirements for GMDSS?

The Global Maritime Distress and Safety System (GMDSS) is a comprehensive international system designed to enhance maritime safety and facilitate rescue operations in emergencies. GMDSS sets requirements for communication equipment on ships to ensure that they can send and receive distress signals, navigate safely, and stay in contact with rescue authorities. Here are the key communication requirements for GMDSS:

Equipment Requirements

1. VHF Radio with DSC (Digital Selective Calling)

  - Channel 70: For sending distress alerts.

  - Channel 16: For distress, safety, and calling.

  - Range: Typically 20-30 nautical miles.

2. MF/HF Radio with DSC

  - Frequencies: Multiple designated distress and safety frequencies.

  - Range: Medium frequency (MF) for up to 400 nautical miles; high frequency (HF) for global coverage.

3. Satellite Communication Systems

  - INMARSAT: For areas within its coverage.

  - GMDSS-approved satellite terminals: For sending and receiving distress alerts and communications via satellites.

4. EPIRB (Emergency Position Indicating Radio Beacon)

  - Frequency: 406 MHz (for distress alerting via satellite).

  - Function: Automatically activates and sends a distress signal with location information to rescue authorities.

5. SART (Search and Rescue Transponder)

  - Frequency: 9 GHz (X-band radar).

  - Function: Helps rescue vessels and aircraft locate the distress position.

6. NAVTEX Receiver

  - Frequency: 518 kHz (international), 490 kHz (national/local language).

  - Function: Receives maritime safety information (MSI), including navigational and meteorological warnings.

7. MF/HF NBDP (Narrow-Band Direct Printing) Receiver

  - Function: For receiving maritime safety information via telex.

8. Survival Craft Transceivers

  - Frequency: VHF Channel 16 and 6.

  - Function: For communication between survival craft and rescue vessels.

9. Two-Way VHF Radiotelephone Apparatus

  - Frequency: VHF maritime mobile band.

  - Function: For on-scene communications during rescue operations.

Operational Requirements

1. Continuous Watch:

  - VHF DSC on Channel 70: All ships must maintain a continuous watch.

  - MF DSC on 2187.5 kHz: Continuous watch in sea areas A2 and beyond.

  - HF DSC on distress frequencies: Continuous watch in sea areas A3 and A4.

  - Satellite EPIRB: Should be operational and monitored.

2. Regular Testing and Maintenance:

  - Routine Checks: Ensure all GMDSS equipment is operational.

  - Battery Maintenance: Check and replace batteries as needed.

  - Software Updates: Keep software up-to-date where applicable.

3. Qualified Personnel:

  - Certification: Operators must have the appropriate GMDSS certification, such as the GMDSS General Operator's Certificate (GOC) or GMDSS Restricted Operator's Certificate (ROC).

  - Training: Regular training and drills to ensure proficiency in using GMDSS equipment.

Sea Areas and Corresponding Equipment Requirements

GMDSS requirements vary depending on the sea area in which the ship operates:

1. Sea Area A1: Within range of a VHF coast station (about 20-30 nautical miles).

  - Required Equipment: VHF radio with DSC, NAVTEX receiver, two-way VHF radiotelephone apparatus.

2. Sea Area A2: Beyond Sea Area A1 but within range of an MF coast station (about 100-150 nautical miles).

  - Required Equipment: VHF radio with DSC, MF radio with DSC, NAVTEX receiver, two-way VHF radiotelephone apparatus.

3. Sea Area A3: Beyond Sea Areas A1 and A2, but within coverage of INMARSAT.

  - Required Equipment: VHF radio with DSC, MF/HF radio with DSC, INMARSAT equipment, NAVTEX receiver, two-way VHF radiotelephone apparatus.

4. Sea Area A4: Areas outside A1, A2, and A3 (primarily polar regions).

  - Required Equipment: VHF radio with DSC, MF/HF radio with DSC, satellite EPIRB, NAVTEX receiver, two-way VHF radiotelephone apparatus.

Conclusion

The GMDSS communication requirements are designed to ensure that ships can send and receive distress alerts, communicate effectively with rescue authorities, and receive vital maritime safety information. Ships must be equipped with specific communication devices based on their operating areas, and operators must be properly trained to use this equipment. This system greatly enhances maritime safety and facilitates efficient rescue operations in emergencies.