FCC Restricted GMDSS (RG) common mistakes
FCC Restricted GMDSS (RG) · Understand the traps and how to avoid them.
Treating the VHF DSC distress alert as the whole distress procedure and waiting for a reply, instead of following the alert with a VHF channel 16 distress call and then moving to a working channel for on-scene traffic.
Candidates learn the button sequence for the DSC alert in isolation and never rehearse the full alert-call-traffic flow, so they think pressing the distress key completes the obligation and forget that the voice call carries the actual information (identity, position, nature of distress, assistance required).
What to do instead
Practice the complete sequence as one routine: lift the cover, press and hold the DSC distress key until the alert transmits, then on channel 16 transmit the distress call and message, then if a coast station or ship acknowledges, shift to the assigned working channel for the on-scene exchange. Recite the sequence aloud until it is automatic, and be able to state what happens if no acknowledgement arrives within about five minutes.
Sending a DSC distress alert on VHF with the wrong position or an unrefreshed position, or without checking that the set is actually on channel 70 with the correct station identity entered.
Under exam pressure candidates focus on the button and skip the pre-transmission checks, and they assume the position comes from the set automatically; in reality the operator must ensure the position and time are up to date (or manually entered) and that the transmitter is on the DSC channel, not on channel 16.
What to do instead
Build a fixed checklist before any alert: confirm the set is on channel 70, confirm the position and UTC time are current, and confirm the correct MMSI is displayed. Learn that a distress alert sent with a wrong or stale position sends rescue assets to the wrong place, and be able to explain how to update position manually when the set has no internal receiver.
Confusing the three alert priorities on DSC and voice: transmitting an urgency (PAN PAN) or safety (SECURITE) message using the distress alert function, or using the distress function for a non-distress problem.
The priority categories look similar on the set menu and candidates memorise the words without linking each to its specific DSC priority code and its specific voice proword, so the categories blur under questioning.
What to do instead
Anchor each priority to one concrete scenario and one code: distress (MAYDAY, DSC distress alert) when a vessel or person is in grave and imminent danger and immediate assistance is required; urgency (PAN PAN, DSC urgency alert) when there is a serious but non-immediate-danger situation such as machinery breakdown or a medical case not immediately life-threatening; safety (SECURITE, DSC safety alert) for navigation or weather warnings. Practise classifying short scenarios into the right category.
Misidentifying which sea area a described vessel is in, and therefore which carriage requirements apply, especially assuming Sea Area A1 requires only a VHF radio.
Candidates memorise the A1-A4 definitions as ranges but do not connect each sea area to the specific equipment set required, and they forget that a vessel in A1 must still be able to receive MSI and carry the appropriate alerting means, not merely a VHF transceiver.
What to do instead
Learn the definitions as one block: A1 within VHF coverage of at least one coast station with continuous DSC alerting; A2 beyond A1 but within MF coverage; A3 beyond A1 and A2 but within Inmarsat coverage (roughly 70 degrees north to 70 degrees south); A4 outside all of these, the polar regions. Then attach the minimum fit for each: an A1 vessel needs VHF with DSC and a means of receiving MSI (such as NAVTEX or an enhanced group call receiver), plus the appropriate distress alerting device such as an EPIRB, and be able to name what changes when the vessel moves into A2 or A3.
Using VHF channel 16 for routine or lengthy on-scene working traffic, or choosing the wrong channel for a specific purpose such as ship-to-ship or port operations.
Channel 16 is the only channel candidates practise on, so they default to it for everything; they have not learned the channel plan and do not realise that 16 is for distress, urgency, safety and calling only, and that working channels must be used for the actual exchange.
What to do instead
Memorise the small set that matters: channel 16 for distress, urgency, safety and calling; channel 70 exclusively for DSC (never voice); channel 13 for bridge-to-bridge navigation safety; channel 06 for ship-to-ship working; channel 09 for routine ship-to-ship and some port operations; channel 12 for port operations in many areas. Practise the habit of announcing on 16 and immediately shifting to a working channel, and be able to state why voice on 70 is prohibited.
Treating NAVTEX as a single stream and being unable to say which message categories it carries, what the message headers mean, or why a station might not be received.
Candidates skim the NAVTEX topic and remember only that it prints weather, missing the structure: the transmitter identity, the message type letter, the message number, and the station's broadcast schedule with its regular times and frequencies.
What to do instead
Learn the message type letters as a set, including navigational warnings, meteorological warnings, ice reports, search and rescue information, meteorological forecasts, pilot service messages and the special categories such as electronic navigational updates and the no-messages and important-messages markers. Be able to read a header line and identify the transmitting station, message category and serial number, and know that NAVTEX uses a single frequency (around 518 kHz for international service) with scheduled transmissions, so a missed message usually means a timing or receiver-setting problem rather than a fault.
Describing EPIRB and SART operation without distinguishing what each does: expecting a SART to alert rescue coordination centres, or expecting an EPIRB to show up on a ship's radar.
Both are emergency devices carried for distress, so candidates merge them into one idea and lose track of the fact that the EPIRB alerts the rescue services through the satellite system while the SART is a local radar transponder that helps a searching vessel or aircraft find the survival craft.
What to do instead
Separate them by function and by who detects them: an EPIRB transmits a distress alert via satellite to a rescue coordination centre, and is registered to the vessel so the identity and contact details are known; a SART responds to X-band radar pulses by producing a line of dots on the searching vessel's radar display, giving bearing and range to the survival craft. Learn the practical points too: the EPIRB is activated manually or by water, must float free and be tested only as permitted, and the SART is switched on in the survival craft and mounted as high as practicable.
Forgetting that the survival craft portable VHF radiotelephone is a distinct item with its own operating constraints, and failing to state how on-scene communications between craft and rescuers are actually conducted.
Candidates treat the survival craft radio as just another VHF set and do not learn its channel limitations, its battery arrangements, or the fact that it is intended for short-range on-scene use rather than long-range alerting.
What to do instead
Learn the survival craft VHF as its own topic: it is a portable, battery-powered set for two-way on-scene communication, typically limited to a small number of channels including channel 16, and its battery must be checked and its seals and lanyard inspected as part of routine maintenance. Be able to describe the on-scene picture: the survival craft communicates with the rescuing ship or aircraft on the agreed channel, keeps transmissions short to conserve battery, and relies on the SART and EPIRB for detection rather than on the handheld set.
Answering licensing and watchkeeping questions from general knowledge rather than from the specific obligations of a restricted operator: what the certificate authorises, what must be entered in the radio log, and what the operator must do on watch.
The regulatory domain feels like common sense, so candidates do not study it, and they assume a restricted certificate allows any GMDSS operation or that log entries are optional record-keeping rather than a regulatory requirement.
What to do instead
Learn the boundary of the authorisation precisely: a restricted operator certificate covers the equipment and sea area for which it is issued and does not authorise operating outside that scope; know that distress, urgency and safety traffic takes absolute priority and that the operator must maintain the required watch on the distress and calling frequencies. For the log, learn the categories of entries that must be recorded, including distress and urgency communications, important incidents, and equipment failures or periods out of service, and be able to say why each entry matters for later investigation.
Giving vague answers on battery care and fault-finding, such as saying batteries should be 'kept charged' without knowing the difference between the main and emergency battery arrangements, or suggesting opening equipment to trace a fault.
Maintenance is treated as a soft topic and candidates never learn the specific practices: that emergency batteries must be kept fully charged and be tested at defined intervals, that terminals and connections need inspection, and that the operator's fault-finding is limited to checks such as power supply, antenna connection, channel setting and obvious physical damage, with repair referred to qualified personnel.
What to do instead
Learn the operator-level routine as a short list: check that the emergency battery is charged and that the charging arrangement is working; inspect terminals for corrosion and tightness; test the set on the required channels as permitted; verify the antenna and its cable are connected and undamaged; confirm the correct channel and any DSC settings. Know the limit of your role: you diagnose and report, you do not repair or open sealed equipment, and you record any failure and the action taken.