RYA SRC/VHF common mistakes
RYA SRC/VHF · Understand the traps and how to avoid them.
Pressing the DISTRESS button on the DSC controller to 'test' it or to see what happens, without first lifting the protective cover and holding the button for the required time, or pressing it a second time when nothing appears to happen.
Candidates confuse the DSC distress button with a general-purpose call button and do not understand that a single press with the cover lifted starts a 5-second countdown to transmission; a second press during the countdown transmits immediately. Nerves during practical assessment make people press again.
What to do instead
Learn the exact sequence: lift cover, press and hold for 5 seconds, watch the countdown on the display, and release only when the set confirms transmission. Practise on a training set until the countdown becomes automatic. If pressed in error, know how to cancel: transmit a voice 'Mayday' cancellation on the distress channel and send a DSC 'distress cancellation' to the same MMSI.
Giving the MMSI as nine digits read out one at a time like a phone number, or inventing a number, or writing the ship's callsign where the MMSI belongs on the radio log and DSC menu.
The MMSI looks like a phone number and candidates default to telephone habits. The distinction between the ship's MMSI (nine digits, starting with the MID), the group MMSI (leading zero) and the individual handheld MMSI is rarely drilled, so the numbers blur.
What to do instead
Memorise the structure: three-digit MID for the flag state, then the ship's identity. Learn that group MMSIs start with 0, coast stations with 00, and that a handheld with its own DSC has its own MMSI. On the exam, write the number in three groups of three and read it digit by digit with 'decimal' or 'repeated' only where relevant. Never guess an MMSI in a distress situation - send an undesignated distress alert instead.
Using the DSC 'distress' function for an urgency (pan-pan) or safety (securite) situation, or sending a routine DSC call on channel 16 instead of on the working channel.
Candidates learn one DSC button and over-apply it. The distinction between distress, urgency, safety and routine priority in the DSC menu is a menu choice, not a button, and it is easy to leave the default on distress.
What to do instead
Learn the four DSC priorities and their voice equivalents: distress (Mayday, immediate danger to life), urgency (Pan-Pan, urgent but no immediate danger), safety (Securite, navigational or meteorological warning), routine. For urgency and safety, select the correct priority in the menu and address the call to 'all ships' or a specific station. For routine ship-to-ship calls, use DSC on the calling channel then move to a working channel for voice.
Treating channel 16 as a working channel: holding a conversation, passing routine traffic, or making a long initial call on 16 instead of moving to a working channel after establishing contact.
Channel 16 is the only channel candidates hear used in examples and training, so it feels like 'the' VHF channel. The requirement to keep it clear for distress, urgency and calling is stated but not practised enough.
What to do instead
Adopt the rule: 16 is for calling and distress only. Make a brief call, agree a working channel (e.g. 06, 08, 72, 77), and switch. Learn the simplex/duplex distinction and the channels reserved for port operations, marinas and ship-to-ship. On the exam, any scenario involving a chat on 16 is a wrong answer.
Failing to distinguish 'Mayday' from 'Pan-Pan' and 'Securite' in the practical voice assessment, or omitting the essential elements of the distress message (identity, position, nature of distress, assistance required, number of persons on board).
The three prowords sound similar and the distress message has five or six mandatory elements. Under assessment pressure candidates rush, skip position or POB, and mix the prowords.
What to do instead
Use a fixed template and practise aloud until it is rote: 'Mayday, Mayday, Mayday, this is [name, callsign, MMSI], Mayday, this is [name], my position is [latitude and longitude or bearing and distance], I am [nature of distress], I require [assistance], I have [number] persons on board, over.' For Pan-Pan and Securite, substitute the proword three times and state the nature of the urgency or the safety message. Record yourself and check every element is present.
Believing an EPIRB or SART transmits continuously once activated, or that a SART shows on the vessel's own radar and can be left on indefinitely, or that a 406 MHz EPIRB is detected by the same receiver as the 121.5 MHz homing signal.
The beacon types are taught as a list of devices rather than as systems with different frequencies and roles. Candidates conflate the 406 MHz satellite alert, the 121.5 MHz homing signal, and the 9 GHz SART radar response.
What to do instead
Learn each device by frequency and function: 406 MHz EPIRB (satellite alert with identity and position, plus 121.5 MHz homing), 121.5 MHz (homing only, not satellite alert), SART (9 GHz radar transponder, range roughly 5-10 nautical miles depending on antenna height, shows as a line of dots on a radar screen, not on a chart plotter). Know battery and test requirements: EPIRB battery typically 48 hours transmit, SART 96 hours standby and 8 hours transmit, and that a SART should only be switched on when survival craft are in the water.
Treating the SRC certificate as optional or assuming a VHF set can be used without a licence, or failing to know that the ship's radio licence and the operator's certificate are separate documents and that both must be on board.
In many countries VHF use is lightly enforced, so candidates underestimate the legal framework. The distinction between the operator certificate (personal) and the ship radio licence (vessel) is not intuitive.
What to do instead
Learn the two-document rule: the operator holds the SRC certificate (or higher), the vessel holds the ship radio licence with the MMSI and callsign. Know that the licence is issued by the flag state, that the SRC is valid for life in most administrations but the licence must be renewed, and that operating without either is an offence. Also know the requirement to keep a radio log where required and to maintain listening watch on 16 and the DSC distress channel.
Misunderstanding DSC alerting and relay: sending a DSC distress relay or acknowledging another vessel's distress alert without authority, or assuming the coast station will always acknowledge and therefore not acknowledging a distress alert received from a vessel.
The DSC acknowledgement rules differ by situation: ships should not acknowledge a distress alert addressed to a coast station, but should acknowledge one addressed to all ships, and should relay if no acknowledgement is received. Candidates learn a single rule and apply it everywhere.
What to do instead
Learn the hierarchy: a distress alert addressed to a specific coast station is acknowledged by that station; ships should not acknowledge but should stand by. An alert addressed to 'all ships' should be acknowledged by ships in the area, and a ship should relay if it hears no acknowledgement after a reasonable time. Never send a distress relay on your own initiative unless you are certain of the distress and no other station has responded.
Ignoring antenna and power basics: assuming range depends only on transmitter power, or not knowing that VHF is essentially line-of-sight and that antenna height, cable loss and connector condition matter more than watts.
Candidates memorise '25 watts maximum' and stop there. The practical consequences of a corroded connector, a coiled cable, or a masthead antenna at 15 metres versus a handheld at 1 metre are not intuitive.
What to do instead
Learn the rule of thumb that VHF range is roughly line-of-sight, about 1.23 times the square root of antenna height in feet, or use the practical figure of 5-10 nautical miles for a masthead antenna and 2-3 for a handheld. Know that a poor connection or water in the coax can halve range, that the antenna must be vertical and clear of metal, and that a handheld should be held upright and away from the head. Check connectors and cable annually.
Not knowing what to do when the DSC distress alert is sent but no voice response follows, or when the radio fails entirely: candidates freeze or repeat the DSC alert instead of escalating to voice Mayday on 16 and alternative means.
Training tends to stop at 'press the button'. The follow-up procedure - voice Mayday on 16, then alternative communications such as 121.5, MF/HF, satellite phone, or mobile - is under-practised.
What to do instead
Learn the escalation ladder: after a DSC distress alert, transmit the voice Mayday on channel 16 with the full message. If no response, repeat at intervals, then try channel 16 on high power, then other distress channels, then alternative means (121.5, portable VHF, satellite, mobile). Know that a DSC alert alone is not a complete distress call and that voice confirmation is expected. Practise the full sequence as a drill, not just the button press.