Select Page

VHF DSC radio Jargon buster

The VHF DSC Radio jargon buster

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.

ALRS

Admiralty List of Radio Signals

ATIS

Automatic Transmitter Identification System

Authorised Operator

The person with the VHF Short Range Certificate who also has an Authority to Operate.

Callsign

Unique letter/number vessel identification number

CG66

Coastguard Yacht and Boat Safety Scheme form

Convention ships

Cargo vessels over 300 Gross Registered Tons and passenger ships that carry 13 or more people.

COSPAS/SARSAT

A satellite-aided search and rescue system designed to locate EPIRBS transmitting on 406 MHz.

Distress

A situation when a vessel, vehicle, aircraft or person is in grave and imminent danger and requests immediate assistance.

DSC

Digital Selective Calling

DTI

Department of Trade and Industry

Dual watch

A facility that allows you to monitor CH16 and one other channel at the same time.

Duplex

Radio working that uses two antennas for working on a two frequency VHF channel.

EPIRB

Emergency Position Indicating Radio Beacon

GHz

Gigahertz

GMDSS

Global Maritime Distress and Safety System

GMT

Greenwich Mean Time

GPS

Global Positioning System

HF

High Frequency

IMO

International Maritime Organisation

INMARSAT

International Mobile Satellite Organisation

ITU

International Telecommunication Union

Mayday

Distress signal. Origin French – m’aidez – help me.

MF

Medium Frequency

MHz

Megahertz

MMSI

9-digit Maritime Mobile Service Identity

Navtex

Maritime safety information broadcast received on 518 KHz and 490kHz as text.

NBDP

Narrow Band Direct-Printing, see Navtex

NMEA interface

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.

PTT

Press to transmit switch

Public Correspondence

Telephone communications

Radio Check

Test call that asks ‘What is the strength and clarity of my transmission?’.

Radio horizon

The distance the radio signal will travel before it reaches the horizon.

RX

Receive

SAR

Search and Rescue

Securite

Safety signal. Origin French – sécurité – safety.

Semi-Duplex

Radio working that uses one antenna to switch between two frequencies on one channel. One frequency for transmitting, the other for receiving.

Simplex

Radio working that uses the same frequency for transmitting and receiving.

Squelch

A radio control that suppresses background interference.

Traffic

Radio messages

TX

Transmitting

UHF

Ultra High Frequency (300–3000MHz)

UKCG

UK Coastguard

Urgency

A situation that is not grave and imminent but serious.

UTC

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.

VHF

Very High Frequency

Voluntary Fit

Vessels that are not ‘Convention Ships’ (see Convention Ships).

VTS

Vessel Traffic Services

Watt

A measure of power output

Find out more about VHF DSC radio operation:

VHF DSC radio operation

Reeds VHF DSC Radio App

First Aid Afloat – fish spine injury

First Aid Afloat - Here is what to do if somebody stands on a fish spine: • Check for dangers. Is it safe for you to enter...

Points of Sailing

The course on which a boat is sailing can be described by its angle to the wind, not to be confused with its compass...

Common marine electrical problems

Most problems with marine electrical systems arise from four possible sources, a lack of maintenance, a poor standard of initial installation, insufficient battery capacity, or ineffective charging systems.
Water ingress is a frequent issue – salt water can corrode contacts very quickly. If connections are not scrupulously clean – or are loose – resistance will be increased, resulting in progressively reduced power.

Essential Yachting + Power Boat Safety Briefing

Yachting Safety Briefing   Down below Lifejackets and harnesses - fitting, when to wear, clipping on Gas - risks,...

Top five windvane self steering installation questions

Top five windvane self steering installation questions answered by Sarah Curry of Hydrovane International Marine, courtesy of Viki Moore from Island Cruising NZ

Know your Navlights & Shapes – essential for all skippers

Know your Navlights & Shapes International Regulations for Preventing Collisions at Sea (ColRegs) Anyone who is...

Sail care and maintenance – Part 2

At the end of the sailing season sails should be washed and inspected carefully for damage, including small tears, stitching failure, ultraviolet damage, stains and mildew.

Boat Improvements

My Boat - practical improvements Author - Mike Rossiter Most boat owners who have had their craft for any length of time will have made what they...

How diesel engines work

The basic principle of a diesel engine is less complex than that of a petrol engine. No spark plug or ignition system is needed, making the basic diesel engine a comparatively straightforward system that results in fewer faults and has lower maintenance costs than a petrol engine.

Boating Rules of the Road – International ColRegs

    International ColRegs Rule 7: Risk of Collision Anyone who is responsible for a vessel at sea, from the...

Cutless bearing replacement

Cutless bearings can last for many years but if the propeller shaft is out of alignment they will wear through more quickly. If you have noticed a clunking sound when motoring then it could be a worn cutless bearing that is causing the problem.

A simple guide to understanding tides when passage planning

Understanding tides when passage planning When planning a trip in tidal waters, check the tides before going afloat. Use...

Boat interior varnishing

Most boat interiors have a combination of varnished and painted surfaces including solid wooden joinery, plywood laminates with thin hardwood veneers and glass reinforced plastic. When making your assessment of what you are going to do, bear in mind that the varnishing process consumes a lot of time, especially if the existing surfaces are in poor shape.

Marine diesel exhaust checks

You should inspect the exhaust system for corrosion damage regularly, especially around the injection bend. If you have noticed the engine exhaust smoking a lot during the sailing season this can also indicate a number of potential problems.

Fire safety advice at sea from the Marine & Coastguard Agency

Fire safety advice for boaters Top fire safety advice at sea: 1. Fit smoke alarms, carbon monoxide and gas detectors 2. Turn...

How to tackle osmosis

Many owners of old GRP boats live in fear of osmosis, but what exactly is osmosis and what can be done about it? Osmosis comes about...

Feeling anxious at sea

  Some people feel anxious at sea. Will they be seasick? What if they get caught in a violent storm? Could the boat...

Safety at sea principles

Safety at sea is not as simple as just spending money adding shiny new emergency equipment such as liferafts, danbuoys, distress flares, EPIRBs and so on.

Tacking a sailing boat

Tacking is the sailing manoeuvre used to change a boat's direction through an oncoming wind. Tacking a sailing boat calls...

First Aid Afloat – how to deal with a fracture at sea

First Aid Afloat A closed fracture does not break through the skin. An open fracture is when the bone punctures it. A...

Getting a tow for your sail or power boat at sea or on inland waterways

FREE tips from the Safe Skipper App for iPhone/iPad/Android: Getting a tow for your sail or power boat Plan how to secure a...

Boatyard Health and Safety

Boat storage facilities are potentially hazardous environments and it is the responsibility of both boat owners and boatyards to ensure that the...

An explanation of the IALA maritime buoyage systems – IALA A and IALA B

What are the differences between the two IALA buoyage systems, IALA Region A and IALA Region B, and where are they used?   As recently as the 1970s...

Winch Servicing

It is not essential to service the winches when a boat is ashore, but if time allows I prefer to do this maintenance job when the boat...

Hull inspection – the annual checks

With the boat ashore for the winter it is time to do a hull inspection - the annual checks. Are there any scratches and chips in the...