Examination Practice Questions And

Coast Guard Global Maritime Distress and Safety System (GMDSS) Radio Operator Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which frequency band is used by MF distress and safety

communications under GMDSS?

• 2–30 MHz
• 300 kHz – 3 MHz
• 30–300 MHz
• 3–30 GHz

Rationale: MF (Medium Frequency) for distress and safety operates

between 300 kHz and 3 MHz. 1 / 4

2. The primary purpose of the GMDSS is to:

• Reduce shipboard maintenance requirements
• Facilitate cargo handling
• Ensure rapid and reliable communication of distress and safety

information

• Improve ship navigation accuracy

Rationale: GMDSS is designed to enhance safety at sea by ensuring

distress signals are transmitted and received efficiently.

• Which of the following is a GMDSS-required distress alerting device on

SOLAS ships?

• AIS Transponder
• VHF Handheld Radio
• EPIRB (Emergency Position Indicating Radio Beacon)
• Radar Transponder

Rationale: EPIRBs automatically send distress signals via satellite to

rescue authorities.

• What does DSC stand for in GMDSS communications?
• Digital Satellite Communication
• Digital Selective Calling
• Direct Safety Channel
• Dynamic Signal Control

Rationale: DSC allows automated transmission of distress alerts and

safety calls. 2 / 4

• Which satellite system is commonly used for GMDSS in the INMARSAT

system?

A. GPS

• Iridium

C. INMARSAT-C

D. COSPAS-SARSAT

Rationale: INMARSAT-C is the primary satellite system for distress,

safety, and general communication.

• The proper DSC distress alert procedure requires the use of which

distress category?

• Urgency
• Safety
• Distress
• Routine

Rationale: The DSC distress alert category is reserved for life-

threatening emergencies.

• What is the VHF channel used for maritime distress, safety, and

calling?

• Channel 16
• Channel 70
• Channel 16 (156.8 MHz)
• Channel 13 3 / 4

Rationale: VHF Channel 16 is internationally designated for distress,

safety, and calling.

• The minimum GMDSS sea area coverage requiring MF/HF radio

stations is:

• Sea Area A1
• Sea Area A2
• Sea Area A3
• Sea Area A4

Rationale: Sea Area A2 extends beyond VHF range but within MF

coverage.

• Which of the following is a function of an NAVTEX receiver?
• Transmit DSC distress alerts
• Receive maritime safety information automatically
• Transmit EPIRB signals
• Provide GPS positioning

Rationale: NAVTEX automatically receives navigational and

meteorological warnings.

• What is the correct procedure when acknowledging receipt of a

DSC distress alert?

• Ignore if not responsible
• Repeat the alert on VHF
• Acknowledge immediately via DSC to the ship in distress
• Send via NAVTEX
• / 4