Maritime Radio

For information on radio operator certificate providers please go to


Maritime Radio Forms:

Ship Radio Licence Application Form

Ship Radio Licence Transfer Form

EPIRB Registration Form

EPIRB Disposal Form


Maritime Radio operating procedures for small craft

General Advice

Radio Operator personnel on small craft should carefully note the following:

  • The international maritime radiotelephony VHF channel for all Distress, Urgency and Safety calls is Channel 16 (156.800 MHz).
  • When vessels are at sea, the VHF Transceiver should be set to Ch16 at all times.
  • If it is necessary for a vessel to monitor a VHF Channel other than CH16, use should be made of the Dual Watch facility on the Transceiver, thus ensuring that a watch is being maintained on VHF CH16 in addition to the second VHF Channel

This information is intended to help the newcomer to marine VHF radio to obtain a radio operator qualification and Ships Radio Licence, (SRL). The term Ships Radio Licence applies to all vessels, irrespective of size.

Before you apply for an SRL you should possess the requisite qualification. In the case of craft fitted with VHF only, the qualification is the Radio Operators Short Range Certificate Module 1, or the old Restricted VHF Certificate.

For vessels fitted with VHF DSC, (digital selective calling), the qualification required is the Radio Operators Short Range Certificate, (SRC), Module 2 or full SRC. If you already possess the old Restricted VHF Certificate or the Radio Operators Short Range Certificate, (SRC), Module 1 you may easily upgrade to Module 2.

Before attempting the examination you should attend a course provided by a recognised course provider. For information on radio operator certificate providers please go to

Possession of a radio operators certificate will enable you to use the correct radio procedure should you be encounter difficulty whilst afloat.


You will be capable of assisting a nearby vessel or person and possibly save a life or lives!!

The ability to use maritime VHF correctly can be a great confidence booster should the unforeseen occur.

Radio Licence and Callsign.

Before you apply for a radio licence you must posses the relevant qualification as outlined in the table on our radio operator examinations page. When a licence is issued you will receive a radio callsign. This item uniquely identifies the vessel and its owner for radiocommunication purposes.

The Irish Coast Guard, (among others), maintains a list of all Irish vessel radio call signs and their owners. It is therefore important to ensure that your licence is correct and up to date.

Another aspect of the licence is that it can be considered as the vessels radio passport. When you send in the licence application we verify that the radio operator is in possession of the appropriate qualification and that the equipment is suitable and up to standard.

If you are cruising abroad and do not have the requisite licence and operator qualification then equipment may be confiscated by the local authorities.

You should ensure that all radio transmitting equipment, which includes radar and EPIRBS, is listed on the application form.

Distress Calls

A Distress Call should always be made on Ch16 and should follow the following format:



Mayday NONSUCH Call Sign EI 1234

Position 15 nautical miles south of Mizen Head (or position in latitude and longitude). My vessel is holed and is taking in water. Immediate assistance required. There are 12 people on board. EPIRB has been deployed. (Give any other information which may be of assistance to the Irish Coast Guard)

The broadcasting of a Distress Call and Distress Message on VHF CH16 should immediately alert the nearest Coast Radio Station and other vessels in the vicinity.

The Coast Radio Station should be the first station to acknowledge receipt of a Distress Call and Distress Message, and vessels should not acknowledge receipt until they are satisfied that a Coast Radio Station has received the message. Vessels in the vicinity of the vessel in distress should then acknowledge receipt of the message.

A Distress Acknowledgement by a vessel should take the following form.


MAYDAY NONSUCH this is Lazy Lad Call Sign EI 1432

Received Mayday

As soon as possible, vessels that acknowledge receipt of a Distress Message should transmit the following information:

  • Name of vessel
  • Position of vessel
  • The speed at which it is proceeding towards, and the approximate time it will take to reach, the vessel in distress.

Small craft that are equipped with VHF Digital Selective Calling (DSC) equipment should note the following:

When there is a need for a vessel to transmit a Distress Alert by DSC, this can be achieved by pressing the Distress and Send buttons on the equipment (on most equipment). The transmission of a DSC Distress Alert is always made on VHF CH70 which is reserved for DSC alerting and calling. The equipment is designed to ensure that a DSC Distress Alert or a DSC Call is always transmitted on VHF CH70 and cannot be transmitted on any other VHF Channel.

The transmission of a DSC Distress Alert in the manner described above includes the identification of the vessel in distress, the position of the vessel in latitude and longitude when the DSC equipment is interfaced with a Position Fixing System such as GPS, and an indication that the vessel concerned is in a distress situation.

Irish Coast Guard Radio Stations which are all fitted with DSC and vessels in the vicinity that are equipped with DSC equipment will receive a DSC Distress Alert, and the Coast Guard can immediately instigate search and rescue procedures.

DSC equipment also allows for the formatting of a Distress Alert to include details of the nature of the distress, e.g. On fire, Sinking, etc. However, in situations where time is of the essence, the method of transmission described above should be employed.

A vessel in distress should broadcast a radiotelephony Distress Message on VHF CH16 immediately following the transmission of a DSC Distress Alert broadcast.

REMEMBER ! Coast Guard Radio Stations do not monitor all VHF Channels such as the Inter-ship channels CH06, CH08, etc. The International VHF Channel 16 and the International DSC VHF Channel 70 have been specifically set aside to assist you to obtain immediate assistance in Distress, Urgency and Safety situations use them!