To operate the radio of a ship fitted with the GMDSS (Global Maritime Distress and Safety System) you need an operator’s certificate. There are two levels: the Restricted Operator’s Certificate (ROC) and the General Operator’s Certificate (GOC). Those preparing for them tend to ask the same thing: what is the exam like, and what do I need to study?
There is little to say about the exam in general: it is set by each country’s administration and run by each school, and course pages almost never detail the format. On the syllabus, however, there is quite a lot in common. This article focuses on that.
Restricted and General: where the difference lies
According to the courses consulted, the Restricted Operator’s Certificate is designed for sea area A1, the area within range of VHF coast stations. The General covers the whole system, and its syllabus includes equipment and services that the Restricted does not touch: MF/HF and satellite services. To review what each sea area means and what equipment is required in each, see the previous article in this series: Sea Areas A1, A2, A3 and A4: What Radio Equipment the GMDSS Requires in Each.
What you study for the Restricted certificate
The programmes of Restricted Operator courses are organised, with minor variations, into four blocks:
- Fundamentals of the maritime mobile service: types of communications, distress, urgency and safety traffic, types of stations, frequencies and bands, VHF propagation, DSC (digital selective calling) and radiotelephony, and the GMDSS distress frequencies.
- Ship station equipment: VHF installations, DSC (format, categories, MMSI number, channel 70), antennas, batteries and emergency power supplies, and the equipment of survival craft: portable VHF, EPIRB and SART.
- Operating procedures: GMDSS structure and sea areas, VHF distress watchkeeping, NAVTEX, EPIRB, SART, sending and acknowledging distress alerts, false alerts, search and rescue operations, urgency and safety communications, and maritime safety information.
- General communications: written and spoken English, the IMO Standard Marine Communication Phrases (SMCP) and the International Code of Signals, the phonetic alphabet, mandatory documentation and the radio log.
Each country also adds its own material. In Argentina, for example, a set of course notes for the Operador Radiotelefonista Restringido en VHF (Restricted VHF Radiotelephone Operator) course covers the regulatory framework and authorities (ITU, ENACOM, IMO, Prefectura Naval), station identification, calling procedures, VHF channels, distress, urgency and safety signals, Q codes and the INTERCO code, secrecy of communications and the Reglamento de Estaciones de Radio Móviles Marítimas (Regulations for Maritime Mobile Radio Stations). The legal basis it cites is Argentina’s National Telecommunications Law, Ley 19.798, which reserves the operation of installations to those who hold an authorisation, licence or certificate.
What the General certificate adds
The General Operator’s syllabus includes everything above and adds, according to the programme of one nautical school consulted:
- MF and HF propagation and bands, and the choice of frequencies according to the time of day.
- Maritime mobile-satellite service, with its terminals and its distress and safety services.
- MF/HF equipment: operation, tuning and selection of frequencies and channels.
- Other GMDSS systems: maritime safety information by NAVTEX and SafetyNET, the 406 MHz EPIRB with the COSPAS-SARSAT system, and SART.
- Search and rescue: rescue coordination centres, the IAMSAR Manual and ship reporting systems.
A caveat: that syllabus also includes narrow-band direct-printing telegraphy (NBDP, or radiotelex), a system that SOLAS chapter IV, in force since 2024, no longer requires. Programmes are updated at different paces, so it is advisable to ask the school which syllabus applies and to check it with the administration.
The practical part
The programmes describe the practical part as a list of tasks the student must be able to perform. According to the course consulted: testing the GMDSS subsystems, sending distress alerts, receiving navigational information, receiving and handling distress calls, cancelling a false alert, and maintaining urgency, safety and general communications, both spoken and written.
In the Restricted Operator courses we consulted, which run to 40 hours, 25 are practical work on a simulator. That gives a clue as to where it is worth putting your study time.
And the exam
The schools describe a theory part, in the classroom, and practical exercises on a simulator. How many questions there are, what mark is needed and who administers it depends on the country and the school, and that information has to be requested from the school or the maritime administration. Nor is it advisable to assume that what holds in one country holds in another: the requirements, procedures and validity periods are set by each administration.
Practising the practical part
Operating radio equipment in a distress situation is learned by doing it. Advenio develops Vox Maris, a GMDSS simulator for training schools, with a DNV Class A (COM) statement of conformity for tables A-IV/2.1 and A-IV/2.2 of the STCW Code. It runs on ordinary PCs over a local network, without dedicated consoles. More information on the Vox Maris product page.
A final note
This article is an orientation guide, not a legal text or the official programme of any course. It summarises what the programmes of several schools describe and does not replace each country’s regulations or the information from the school or the administration that issues the certificate.
Sources: programmes and course descriptions from Cenáutica, Escuela Balear de Náutica, Escola Port Barcelona and Sailwiz (Spain); course notes Reglamentación para Operador Radiotelefonista Restringido en VHF and course description, CECAFOM (Argentina); IMO, Model Course 1.26, Restricted Operator’s Certificate for GMDSS, 2025 edition.