VHF DSC RADIO

• Have a VHF DSC (Digital Selective Calling) radio on your boat and learn how to use it.
• Make sure your radio license is up to date with OFCOM, this is free online. This includes your MMSI, call sign and any other radio equipment onboard. This is vital when you are buying a boat with radio equipment already installed.
• Ensure your GPS position is linked to your DSC (if fitted).

With DSC you can send a distress alert along with your exact position, with one touch of the button, this is repeated until it is acknowledged by a Coastguard Station or a vessel. Make sure your GPS is checked and calibrated. If no GPS is connected make sure you manually update your position.

Maritime Mobile Service Identity (MMSI) numbers are programmed into a DSC radio. Details include up to date information for the vessel including 24hr emergency contact details.
Visit www.ofcom.org.uk or phone 0300 123 3333.

All UK MRCCs have access to the MMSI database. If you use the CG66 scheme please ensure your radio details (MMSI and callsign are up to date.)

Make sure your radio licence is up to date with OFCOM, this is free online. This includes your MMSI, callsign and any other radio equipment onboard. This is vital when you are buying a boat with radio equipment already installed.

Ensure your GPS position is linked to your DSC (if fitted). If no GPS is connected make sure you manually update your position.

Your (MMSI) number is programmed into a DSC radio. Details include up to date information for the vessel including 24hr emergency contact details. Visit www.ofcom.org.uk or phone 0300 123 3333.

If a vessel or person gets into difficulty the alarm should be raised by what ever means possible.

Generally in UK waters out to 30 miles, VHF DSC is the preferred method of distress alerting but also for urgency, safety and routine calling to all our UK Maritime Rescue Coordination Centres.

Think of the DSC as an alerting or paging system both on the vessel and ashore at the rescue centres. It is the initial call prior to normal radio telephony. DSC is has no language barrier being an international standard.

HM Coastguard currently operates a VHF Channel 16 listening watch but there may be limitations for sailors only using VHF RT.

Will your VHF call be heard?

Your VHF transmission may not be heard because it can be overridden by a stronger simultaneous transmission which you may not heard yourself, whereas the DSC call will be delivered despite interference from other transmissions.

You don’t have to keep listening watch

DSC will alert you when you are contacted so you don’t have to keep a listening watch on VHF channel 16.

Saves time in an emergency

There are search and rescue benefits for sailors using DSC in an emergency:

At a touch of a button, your position is sent along with a distress alert, and rescuers will then be listening out for your voice distress message on channel 16 (if you have time to make one).

The Maritime and Coastguard Agency has made a significant investment in refreshing the DSC infrastructure both at VHF and MF. Using this technology, HM Coastguard now have the ability to poll a geographic area to get a position for vessels that are installed with DSC (and linked to a GPS).

Additionally, this technology gives HM Coastguard the ability to automatically respond to DSC test calls, giving the boat user the confidence that their DSC unit is functioning correctly.

1. Obtaining MMSI numbers: programme your DSC with the relevant Coastguard MMSI numbers and other routine shore station contacts. If you have AIS fitted on your vessel the AIS receiver will give you MMSI numbers to contact AIS equipped vessels in your immediate area.

2. Tricky to get to grips with using DSC. Get your radio licence and complete a SRC (Short Range Certificate) course during which you will be trained on the correct use of DSC. Use the DSC for routine calling to other vessels and shore stations to become more familiar with your equipment. This will also help reduce false alerts. Different manufacturers create different interfaces so the unit you train on may not be the same as your own DSC on your boat. Make sure you have the latest instruction manual for your set, often available from the manufacturers website.

MCA’s Search and Rescue Communications Manager Steve Huxley says: ‘Like any technical equipment such as your computer or a new mobile phone, you will become familiar with it, the more you use it.’

MCA website

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