If you are comparing GMDSS GOC vs ROC, the short version is that the GOC covers the full Global Maritime Distress and Safety System and the ROC covers only VHF within sea area A1. Which one you need depends on where your ship trades and what certificate you are working towards, including the Officer of the Watch route.
Key points
- GMDSS is the international system for distress alerting and safety communications; STCW sets the operator certificates.
- The GOC (General Operator's Certificate) covers all GMDSS equipment, including MF/HF and satellite, and is for voyages beyond sea area A1.
- The ROC (Restricted Operator's Certificate) is VHF-based and for ships that stay within sea area A1.
- Deck officer routes, including OOW on yachts, call for the GOC. The MCA has issued UK GOC and ROC certificates directly since May 2025 (AMERC did so before), and STCW endorsements are revalidated every five years.
What is GMDSS?
The Global Maritime Distress and Safety System is the IMO's framework for sending and receiving distress alerts, maritime safety information and ship-to-shore communications. It replaced the old reliance on Morse code and ships listening on watch. A ship's equipment depends on which sea areas it trades in, and the operator certificates match those areas.
The sea areas
| Sea area | Rough meaning | Main communications |
|---|---|---|
| A1 | Within range of a coast VHF station with continuous DSC alerting | VHF DSC |
| A2 | Beyond A1, within range of a coast MF station | MF DSC and VHF |
| A3 | Beyond A2, within coverage of geostationary satellites | Satellite, plus MF/HF |
| A4 | Polar regions beyond satellite coverage | HF |
The exact coverage of each area is set by the coastal state, so two coasts can have different sea areas. Your captain and the vessel's radio equipment list will tell you which area applies.
GOC vs ROC: the differences
| GOC | ROC | |
|---|---|---|
| Full name | General Operator's Certificate | Restricted Operator's Certificate |
| Equipment covered | The full GMDSS fit, including MF/HF and satellite systems | VHF equipment and procedures |
| Sea areas | All sea areas, including beyond A1 | Sea area A1 only |
| Typical users | Officers and masters on ocean-going or foreign-going ships | Officers and crew on ships that stay within VHF range |
| STCW basis | Regulation IV/2 and Section A-IV/2 | Regulation IV/2 and Section A-IV/2 |
Both sit under STCW Regulation IV/2. The GOC is the higher certificate. There is also a separate Long Range Certificate (LRC), which is not an STCW requirement, so most professional seafarers can ignore it.
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Who needs which?
- Deck officers on SOLAS ships trading beyond A1: the GOC. Training providers describe it as the certificate masters and deck officers on ocean-going ships hold under STCW.
- Merchant Navy deck cadets: the GOC is typically built into the cadet programme.
- Yacht officers: the OOW (Yachts less than 3000gt) route lists the GMDSS GOC among the required courses.
- Vessels staying within A1: the ROC may meet the requirement, depending on the vessel's certificate, flag and manning rules. Check the manning requirements for your vessel.
- Small vessels and leisure use: the RYA Short Range Certificate (SRC), a VHF certificate, is the normal qualification for skippers and is accepted as the GMDSS-compliant radio certificate for the Yachtmaster and commercial endorsement.
If you aim to be an officer on any larger vessel, the safest plan is to take the GOC. It covers everything the ROC does, so you will not need to retake it later.
How long are the courses?
Course lengths depend on the approved training provider and the course type. As a rough guide, UK providers run the GOC over 8 to 10 days (two weeks at many colleges) with practical sessions on simulated equipment and an examination at the end. The ROC is shorter, typically three days plus the exam. Check each provider's current timetable, and note that the MCA requires a course completion certificate from an approved provider before it will issue the certificate.
How to get your certificate
- Complete a GMDSS course with an MCA-approved provider.
- Apply to the MCA on form MSF 4354 with your course completion certificate, two photos, an attested passport copy and the fee (£77 plus courier at the time of writing, per MIN 716), emailed to the MCA GMDSS team. The MCA aims to process applications in 14 days.
- For a UK STCW endorsement you also need a valid ENG1 (see our ENG1 medical guide) and the four STCW basic training certificates or a UK certificate of competency.
If you apply for the GOC or ROC with a UK deck certificate of competency, you do not need a separate application: it is done alongside your CoC application.
A note on who issues what. Until April 2025 the Association of Marine Electronic and Radio Colleges (AMERC) ran the exams and issued UK GMDSS certificates on the MCA's behalf, which is why older certificates carry its name. Under MIN 716, since 12 May 2025 MCA-approved centres run the course and exam and you apply to the MCA directly. Ofcom is not involved in operator certificates: it issues the Ship Radio Licence for the vessel's radio station, which is a separate matter from your personal certificate.
Revalidation
Your STCW endorsement must be revalidated every five years. The MCA asks for a copy of your GMDSS certificate and valid medical, plus either a certified copy of your CoC or evidence of up-to-date personal survival techniques and fire prevention and firefighting training in the last five years. Keep your STCW Basic Safety in date.
Why the choice matters
Taking the ROC first looks cheaper and quicker, and for crew on small vessels that stay close to the coast it may be exactly right. The problem comes later. A deck officer certificate, an OOW or a master's ticket, assumes you can operate the complete GMDSS fit, and a ship that trades beyond A1 needs officers who hold the GOC. If you take the ROC and then move to a bigger vessel, you will have to do the GOC anyway. If your plan is any kind of officer career, go straight to the GOC and be done with it.
It is also worth remembering that holding a certificate and being good on the radio are different things. Distress alerts, urgency and safety calls, the DSC controller, EPIRB and SART tests, and routine communications are all areas where practical competence counts. Practise on the real equipment aboard whenever you have the chance, and ask the officer of the watch to walk you through the weekly tests and the contents of the radio log.
How GMDSS fits the OOW route
For the OOW (Yachts less than 3000gt) certificate, MSN 1858 (Amendment 2) requires the four STCW basic safety certificates, Proficiency in Survival Craft and Rescue Boats, ECDIS, HELM (Operational), the Efficient Deck Hand certificate and the GMDSS GOC, alongside the two MCA written exams (Navigation and Radar; General Ship Knowledge) and the oral. Medical First Aid, Advanced Fire Fighting and Medical Care come later, for Chief Mate and Master. The GOC is not something to leave to the last moment, as your Notice of Eligibility will not be processed without the full set. The OOW oral may also include radio and distress procedures, so read our OOW oral exam guide and our guide to becoming an OOW on yachts.
Frequently asked questions
What is the difference between GOC and ROC?
The GOC covers the full GMDSS equipment fit, including MF/HF and satellite, for all sea areas. The ROC covers VHF only for sea area A1.
Do I need a GOC for OOW?
Yes. For the OOW (Yachts less than 3000gt) route, MSN 1858 lists the GMDSS GOC as a required ancillary certificate, and MSN 1864 says a deck officer CoC needs the GOC, with the ROC accepted only for some near coastal certificates.
How long does GMDSS certification last?
The GOC and ROC are certificates from the course, but your STCW endorsement has to be revalidated every five years.
Is the RYA SRC the same as the ROC?
No. The SRC is a VHF certificate for leisure and small commercial use, and the ROC is the STCW restricted operator's certificate. Check which your vessel or endorsement requires.
Who issues the certificate?
Since May 2025 the MCA issues UK GOC and ROC certificates and STCW endorsements directly, after you pass the exam at an MCA-approved centre. Before that AMERC issued them on the MCA's behalf. Ofcom licenses the ship's radio station, not the operator.
Can I take the GOC if I only have the ROC?
Yes, you can take the GOC course. Ask your provider whether your ROC reduces the course length.
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