IALACOLREG

GMDSS — General Operator's Certificate preparation

Complete GMDSS General Operator's Certificate preparation: fundamentals, sea areas A1-A4, VHF-DSC, MF/HF-DSC, satellite, NAVTEX, EPIRB, SART, Mayday/Pan-Pan/Sécurité procedures, maritime English, radio log and drills.

1

Phase 1 — Fundamentals

8 h theory · 5 h practice
2

Phase 2 — Equipment

29 h theory · 47 h practice
3

Phase 3 — Procedures

11 h theory · 13 h practice
4

Phase 4 — Integrated drills

1 h theory · 5 h practice

GMDSS — what the General Operator's Certificate actually tests

The Global Maritime Distress and Safety System (GMDSS) is the worldwide framework of radio equipment, satellites and procedures that turns "someone is in trouble" into "the right SAR authority knows, the right vessels can divert, and the right traffic gets out of the way." Adopted by the IMO in 1988 and fully effective from 1999, it replaced Morse-code distress with automated, multi-band alerting.

Operators of vessels fitted with GMDSS equipment in sea areas A2, A3 or A4 (in practice, any ship subject to SOLAS Chapter IV and many large yachts) must hold a GOC — the General Operator's Certificate. The course covers four blocks: fundamentals (sea areas, frequencies, regulations), equipment (DSC controllers, MF/HF transceivers, Inmarsat-C, NAVTEX, EPIRBs, SARTs, AIS-SART), procedures (Mayday, Mayday Relay, Pan-Pan, Sécurité, urgency cancellations, on-scene comms) and integrated drills.

Below you'll find all 15 modules in the order most national exam boards (Spain DGMM, UK MCA, US FCC) teach them. Theory hours and practice hours are taken from the IMO Model Course 1.25 baseline. The visual radio-procedure cards and Mayday templates are designed to be screenshotted and laminated.

GMDSS sea areas at a glance

AreaCoverageRequired equipment
A1Within range of at least one VHF coast station with continuous DSC alerting (≈ 20–30 NM)VHF radio with DSC (Ch 70 watch) + EPIRB + SART
A2Beyond A1, within range of at least one MF coast station with continuous DSC (≈ 100–150 NM)A1 equipment + MF radio with DSC (2187.5 kHz watch)
A3Beyond A2, within Inmarsat geostationary satellite coverage (~ 70° N to 70° S)A2 equipment + Inmarsat-C OR HF radio with DSC
A4Polar regions outside Inmarsat coverage (above 70° N / below 70° S)A3 equipment + HF radio with DSC mandatory + redundant HF

Most-asked GMDSS modules

Frequently asked questions

What is the difference between sea areas A1, A2, A3 and A4?
They define how far from shore you are, and therefore which radio equipment you must carry. A1 is within VHF coverage (~20-30 NM). A2 is within MF coverage (~100-150 NM). A3 is within geostationary Inmarsat coverage (roughly 70° N to 70° S). A4 is the polar regions outside Inmarsat coverage and requires HF radio with DSC.
What does GOC stand for?
General Operator's Certificate. It is the GMDSS qualification required of operators on ships and yachts certified to operate in sea areas A2, A3 or A4. Below GOC sits the ROC (Restricted Operator's Certificate) which only authorises A1 operations using VHF-DSC. LRC is the recreational long-range certificate accepted in many leisure jurisdictions.
What is the difference between Mayday, Pan-Pan and Sécurité?
Mayday is a DISTRESS call — grave and imminent danger requiring immediate assistance. Pan-Pan is an URGENCY call — a serious situation that does not yet require immediate assistance (e.g. a man overboard situation under control, a medical evacuation request, a steering failure in clear water). Sécurité is a SAFETY call — navigational hazard or important meteorological warning. The format and frequencies differ.
Is GMDSS still required if I have a smartphone and satellite messenger?
For SOLAS-class vessels, yes — GMDSS is mandatory and a satellite messenger or smartphone is not a substitute. For recreational yachts, a 406 MHz EPIRB and a VHF with DSC are the minimum credible distress kit; satellite messengers (Garmin inReach, Iridium GO!) are useful supplements but they are NOT in the GMDSS framework and SAR authorities will not always treat them with the same priority.
What is an AIS-SART and how is it different from a radar SART?
A radar SART (Search and Rescue Transponder) responds to 9 GHz radar pulses with a distinctive 12-blip line. An AIS-SART transmits AIS messages identifying itself as a survival-craft beacon, plottable on any AIS receiver including ECDIS. Modern survival craft typically carry an AIS-SART; some carry both.