GMDSS GOC Flashcards: Radio Concepts and Terminology
80 original English cards for maritime radio trainees: GMDSS terms, current sea-area concepts, selected channels, identification, MSI and alerting distinctions.
Mayelana naleli qoqo
Practise 80 original English concept cards for GMDSS GOC revision. The scope is a selected theory subset referenced to the active CEPT ERC/DEC/(99)01 Annex 1 syllabus, amended 8 March 2024. It is not a complete GOC course or a national examination guide. Reviewed for 2026; sea-area concepts reflect the SOLAS changes effective 1 January 2024.
Recall a term’s meaning or function, identify selected channel/frequency uses, interpret basic MMSI patterns and NAVTEX header fields, and distinguish concepts in six short reasoning prompts. Selected applications revisit DSC channel use, HF propagation, ship-specific A3 coverage, NAVTEX coverage versus service area, voyage planning and the limits of beacon return-link confirmation. Basics come before dependent cases; related variants are separated by at least three unrelated cards. The app schedules later repetition. Public tags are gmdss plus basics, radio, safety-info or alerting.
Excluded: complete emergency scripts and action sequences; distress acknowledgement, relay and cancellation procedures; live testing; equipment operation or repair; full communication drills; national eligibility, renewal and carriage rules; billing and complete examination coverage. Those tasks need current approved training, vessel procedures, publications and the actual equipment manual. Flashcard recall does not establish practical competence, certification or readiness to manage an emergency.
All questions and answers were independently written with AI assistance and checked against public authoritative factual sources. The cover is an original AI-generated illustration, not an equipment guide. No examination questions, mark schemes or curriculum text were copied. CC0 applies only to original expression, organisation, metadata and generated media to the extent applicable rights exist; it does not license source publications or claim ownership of facts.
Independent, unofficial study material by Open Study Contributor. No affiliation with or endorsement by CEPT/ECC, IMO, ITU, Inmarsat, Iridium or any certification authority is claimed. See the official CEPT syllabus and implementation information; national requirements must be checked with the relevant administration.
Amakhadi akuleli qoqo
Ikhadi 1
Umbuzo
In maritime radio, what does GMDSS stand for?
Impendulo
Global Maritime Distress and Safety System.
Ikhadi 2
Umbuzo
In the CEPT maritime-radio syllabus, what does GOC stand for?
Impendulo
General Operator’s Certificate.
Ikhadi 3
Umbuzo
What does a radio frequency of 1 Hz represent?
Impendulo
One cycle per second.
Ikhadi 4
Umbuzo
In GMDSS, what does MSI stand for?
Impendulo
Maritime Safety Information.
Ikhadi 5
Umbuzo
Which international organisation develops the maritime safety framework behind GMDSS?
Impendulo
The International Maritime Organization (IMO).
Ikhadi 6
Umbuzo
Which international organisation maintains the Radio Regulations used by maritime radio services?
Impendulo
The International Telecommunication Union (ITU).
Ikhadi 7
Umbuzo
GMDSS combines which two broad communication paths?
Impendulo
Terrestrial radio and satellite communication.
Ikhadi 8
Umbuzo
In maritime radio, what does DSC stand for?
Impendulo
Digital Selective Calling.
Ikhadi 9
Umbuzo
Which maritime emergency category means grave and imminent danger requiring immediate assistance?
Impendulo
Distress.
Ikhadi 10
Umbuzo
What is the purpose of NAVTEX?
Impendulo
Automatic reception of broadcast maritime safety information as text.
Ikhadi 11
Umbuzo
In maritime radio, what does MMSI stand for?
Impendulo
Maritime Mobile Service Identity.
Ikhadi 12
Umbuzo
In maritime satellite communications, what does SES stand for?
Impendulo
Ship Earth Station: the satellite-communication station aboard a ship.
Ikhadi 13
Umbuzo
In maritime safety, what does EPIRB stand for?
Impendulo
Emergency Position-Indicating Radio Beacon.
Ikhadi 14
Umbuzo
How many hertz are in 1 kHz?
Impendulo
1000 Hz.
Ikhadi 15
Umbuzo
In maritime communications, what does SAR stand for?
Impendulo
Search and Rescue.
Ikhadi 16
Umbuzo
What is the basic role of maritime DSC?
Impendulo
Establishing contact and transferring calling or alert information using digital codes.
Ikhadi 17
Umbuzo
In radio spectrum terminology, what does MF mean?
Impendulo
Medium frequency: 300 kHz to 3 MHz.
Ikhadi 18
Umbuzo
What is the international NAVTEX frequency?
Impendulo
518 kHz.
Ikhadi 19
Umbuzo
How many digits does an MMSI contain?
Impendulo
Nine digits.
Ikhadi 20
Umbuzo
Which category concerns an urgent safety message without the distress condition requiring immediate assistance?
Impendulo
Urgency.
Ikhadi 21
Umbuzo
In radio spectrum terminology, what does HF mean?
Impendulo
High frequency: 3 to 30 MHz.
Ikhadi 22
Umbuzo
In GMDSS, what does RMSS mean?
Impendulo
Recognised Mobile Satellite Service: a satellite service recognised by IMO for GMDSS.
Ikhadi 23
Umbuzo
How many kilohertz are in 1 MHz?
Impendulo
1000 kHz.
Ikhadi 24
Umbuzo
In a NAVTEX header, what does B1 identify?
Impendulo
The transmitter.
Ikhadi 25
Umbuzo
In radio spectrum terminology, what does VHF mean?
Impendulo
Very high frequency: 30 to 300 MHz.
Ikhadi 26
Umbuzo
Which category announces navigation-safety information or important meteorological warnings?
Impendulo
Safety.
Ikhadi 27
Umbuzo
Which radio coverage defines GMDSS sea area A1?
Impendulo
VHF coast-station voice coverage with continuous DSC alerting, as defined by a Contracting Government.
Ikhadi 28
Umbuzo
What do the Maritime Identification Digits in an MMSI identify?
Impendulo
The administration with jurisdiction over the station.
Ikhadi 29
Umbuzo
In a NAVTEX header, what does B2 identify?
Impendulo
The message subject category.
Ikhadi 30
Umbuzo
Which spoken maritime radio signal denotes distress?
Impendulo
MAYDAY.
Ikhadi 31
Umbuzo
Which radio coverage defines GMDSS sea area A2?
Impendulo
MF coast-station voice coverage with continuous DSC alerting, outside A1, as defined by a Contracting Government.
Ikhadi 32
Umbuzo
What atmospheric region enables HF skywave communication beyond the horizon?
Impendulo
The ionosphere.
Ikhadi 33
Umbuzo
What do the B3B4 characters in a NAVTEX header represent?
Impendulo
The two-digit message number.
Ikhadi 34
Umbuzo
Which spoken maritime radio signal denotes urgency?
Impendulo
PAN PAN.
Ikhadi 35
Umbuzo
Since 1 January 2024, what determines a ship’s GMDSS sea area A3?
Impendulo
Its carried ship earth station’s recognised mobile satellite service coverage with continuous alerting, outside A1 and A2.
Ikhadi 36
Umbuzo
Which language is used by the international NAVTEX service on 518 kHz?
Impendulo
English.
Ikhadi 37
Umbuzo
In ITU radio terminology, how do the two directions operate in simplex communication?
Impendulo
Alternately: one direction transmits at a time.
Ikhadi 38
Umbuzo
Which spoken maritime radio signal introduces safety traffic?
Impendulo
SÉCURITÉ (SECURITE).
Ikhadi 39
Umbuzo
How is GMDSS sea area A4 defined?
Impendulo
The area outside A1, A2 and that ship’s A3.
Ikhadi 40
Umbuzo
Which NAVTEX subject category does B2 = A represent?
Impendulo
Navigational warnings.
Ikhadi 41
Umbuzo
In ITU radio terminology, what does duplex operation permit?
Impendulo
Simultaneous transmission in both directions.
Ikhadi 42
Umbuzo
What is the priority order of distress, urgency, safety and routine radio traffic?
Impendulo
Distress → urgency → safety → routine.
Ikhadi 43
Umbuzo
Which marine VHF channel is reserved for DSC?
Impendulo
Channel 70, 156.525 MHz; it is not a voice channel.
Ikhadi 44
Umbuzo
Which NAVTEX subject category does B2 = B represent?
Impendulo
Meteorological warnings.
Ikhadi 45
Umbuzo
Which frequency band identifies the satellite distress-alerting function of a modern EPIRB?
Impendulo
406 MHz.
Ikhadi 46
Umbuzo
What are bridge-to-bridge communications in GMDSS terminology?
Impendulo
Safety radio communications between ships from their navigating positions.
Ikhadi 47
Umbuzo
Which marine VHF channel carries radiotelephony distress and safety traffic?
Impendulo
Channel 16, 156.8 MHz.
Ikhadi 48
Umbuzo
Which NAVTEX subject category does B2 = E represent?
Impendulo
Meteorological forecasts.
Ikhadi 49
Umbuzo
What does integrated GNSS add to an EPIRB distress alert?
Impendulo
An encoded position from a Global Navigation Satellite System, helping rescuers locate the beacon.
Ikhadi 50
Umbuzo
Which GMDSS communication function concerns units at the incident location?
Impendulo
On-scene communications.
Ikhadi 51
Umbuzo
Which MF frequency is used for DSC distress and safety calling?
Impendulo
2187.5 kHz.
Ikhadi 52
Umbuzo
Which NAVTEX subject category does B2 = C represent?
Impendulo
Ice reports.
Ikhadi 53
Umbuzo
Why does accurate EPIRB registration help rescue authorities?
Impendulo
It links the beacon identity to vessel and contact information.
Ikhadi 54
Umbuzo
What is the purpose of a GMDSS reserve source of energy?
Impendulo
Powering distress and safety radio equipment if main and emergency electrical supplies fail.
Ikhadi 55
Umbuzo
Which MF frequency is used for radiotelephony distress and safety communications?
Impendulo
2182 kHz.
Ikhadi 56
Umbuzo
Name the lower-frequency national NAVTEX channel distinct from international 518 kHz.
Impendulo
490 kHz; availability and language depend on the national service.
Ikhadi 57
Umbuzo
What is the role of an EPIRB’s low-power 121.5 MHz signal?
Impendulo
Local homing by rescue units; Cospas-Sarsat satellites no longer process 121.5 MHz alerts.
Ikhadi 58
Umbuzo
Does the CEPT GOC syllabus assess theory alone?
Impendulo
No. It requires theoretical and practical tests.
Ikhadi 59
Umbuzo
At the same wave speed, what happens to wavelength when frequency rises?
Impendulo
Wavelength becomes shorter.
Ikhadi 60
Umbuzo
In maritime satellite safety broadcasts, what does EGC stand for?
Impendulo
Enhanced Group Call.
Ikhadi 61
Umbuzo
What is the purpose of a float-free EPIRB’s hydrostatic release?
Impendulo
Releasing the beacon from its bracket when submerged, so it can float free.
Ikhadi 62
Umbuzo
Why does GMDSS communication planning consider the whole voyage?
Impendulo
Service coverage, relevant stations and safety-information areas can change along the route.
Ikhadi 63
Umbuzo
What is the standard ship-station MMSI pattern, using MID and X placeholders?
Impendulo
MIDXXXXXX: three Maritime Identification Digits followed by six digits.
Ikhadi 64
Umbuzo
Which named Inmarsat service broadcasts maritime safety information?
Impendulo
SafetyNET.
Ikhadi 65
Umbuzo
Does a beacon Return Link Service (RLS) indication mean a rescue has been launched?
Impendulo
No. It confirms receipt, localisation and forwarding of the alert, not launch of a rescue.
Ikhadi 66
Umbuzo
Two ships share a position outside A1/A2 but carry different RMSS terminals. Must their A3 coverage match?
Impendulo
No. A3 depends on the RMSS supported by each ship’s carried earth station.
Ikhadi 67
Umbuzo
What is the coast-station MMSI pattern, using MID and X placeholders?
Impendulo
00MIDXXXX: two leading zeros, the MID, then four digits.
Ikhadi 68
Umbuzo
Which named Iridium service broadcasts maritime safety information?
Impendulo
SafetyCast.
Ikhadi 69
Umbuzo
Why use an EPIRB’s approved self-test instead of ordinary activation for practice?
Impendulo
Ordinary activation can transmit a real distress alert and divert rescue resources.
Ikhadi 70
Umbuzo
What is a NAVAREA used to coordinate?
Impendulo
Navigational warnings for a defined sea area.
Ikhadi 71
Umbuzo
What is the primary role of a radar SART?
Impendulo
Helping nearby rescue units locate survivors through a radar response. SART means Search and Rescue Transponder.
Ikhadi 72
Umbuzo
A training question asks for voice transmission on VHF channel 70. What is the conceptual error?
Impendulo
Channel 70 is for DSC, not radiotelephony.
Ikhadi 73
Umbuzo
What is a METAREA used to coordinate?
Impendulo
Marine meteorological warnings and forecasts for a defined sea area.
Ikhadi 74
Umbuzo
Which IAMSAR volume is intended for vessels and other mobile facilities?
Impendulo
Volume III, Mobile Facilities.
Ikhadi 75
Umbuzo
Why can an HF link become unreliable during disturbed space weather?
Impendulo
Changes in the ionosphere can degrade or disrupt HF propagation.
Ikhadi 76
Umbuzo
Which radar band does a GMDSS radar SART use?
Impendulo
9.2–9.5 GHz, in the 9 GHz/X-band radar region.
Ikhadi 77
Umbuzo
Why is preventing false distress alerts a safety issue?
Impendulo
False alerts can divert search-and-rescue resources from real emergencies.
Ikhadi 78
Umbuzo
Does receiving a NAVTEX transmitter’s signal prove that every received warning concerns the ship’s position?
Impendulo
No. Radio coverage and the transmitter’s defined service area are different concepts.
Ikhadi 79
Umbuzo
A training display says an RLS alert was received. What rescue outcome must not be inferred?
Impendulo
That rescue units have already been dispatched or will arrive at a particular time.
Ikhadi 80
Umbuzo
How does an AIS-SART provide a locating signal?
Impendulo
By transmitting search-and-rescue locating information on Automatic Identification System (AIS) frequencies.
amakhadi angu-80
GMDSS GOC Flashcards: Radio Concepts and Terminology
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