AIS – Automatic Identification System
This system is used by shipping. It allows another vessel or coast station to use equipment that can interrogate the radio in order to learn the course, speed, type of vessel, cargo, etc. It is also available to recreational vessels.
Admiralty List of Radio Signals
Automatic Transmitter Identification System
The person with the VHF Short Range Certificate who also has an Authority to Operate.
Unique letter/number vessel identification number
Coastguard Yacht and Boat Safety Scheme form
Cargo vessels over 300 Gross Registered Tons and passenger ships that carry 13 or more people.
A satellite-aided search and rescue system designed to locate EPIRBS transmitting on 406 MHz.
A situation when a vessel, vehicle, aircraft or person is in grave and imminent danger and requests immediate assistance.
Digital Selective Calling
Department of Trade and Industry
A facility that allows you to monitor CH16 and one other channel at the same time.
Radio working that uses two antennas for working on a two frequency VHF channel.
Emergency Position Indicating Radio Beacon
Global Maritime Distress and Safety System
Greenwich Mean Time
Global Positioning System
International Maritime Organisation
International Mobile Satellite Organisation
International Telecommunication Union
Distress signal. Origin French – m’aidez – help me.
9-digit Maritime Mobile Service Identity
Maritime safety information broadcast received on 518 KHz and 490kHz as text.
Narrow Band Direct-Printing, see Navtex
Marine industry standard method of connecting one piece of electronic equipment to another, eg GPS with autopilot. Pan Pan–Urgency signal. Origin French – en panne – in difficulty.
Press to transmit switch
Test call that asks ‘What is the strength and clarity of my transmission?’.
The distance the radio signal will travel before it reaches the horizon.
Search and Rescue
Safety signal. Origin French – sécurité – safety.
Radio working that uses one antenna to switch between two frequencies on one channel. One frequency for transmitting, the other for receiving.
Radio working that uses the same frequency for transmitting and receiving.
A radio control that suppresses background interference.
Ultra High Frequency (300–3000MHz)
A situation that is not grave and imminent but serious.
Universal Co-ordinated Time. This is also known as GMT (Greenwich Mean Time). This is the basis for all calculations of time and it is the time shown on the display of a VHF-DSC radio. Times around the world are all related to UTC.
Very High Frequency
Vessels that are not ‘Convention Ships’ (see Convention Ships).
Vessel Traffic Services
A measure of power output