RYA SRC DSC Operations

Question 1

What does 'DSC' stand for in marine radio communications?

Accepted Answer

Digital Selective Calling

Answer

DSC stands for Digital Selective Calling. It is a digitally encoded signalling system that allows radio operators to send automated alerts and calls to specific stations or all stations.

Question 2

On which VHF channel are DSC calls transmitted?

Accepted Answer

Channel 70

Answer

All VHF DSC calls are transmitted and received on Channel 70 (156.525 MHz). This channel is dedicated exclusively to DSC traffic and should never be used for voice communications.

Question 3

What is an MMSI number and why is it important for DSC?

Accepted Answer

A unique nine-digit Maritime Mobile Service Identity that identifies a specific vessel or coast station in the DSC system

Answer

An MMSI (Maritime Mobile Service Identity) is a unique 9-digit number assigned to each DSC-equipped vessel or coast station. It acts like a telephone number, allowing specific calls to be made.

Question 4

What happens when you press the dedicated 'DISTRESS' button on a DSC VHF radio?

Accepted Answer

It sends an automated distress alert on Channel 70 containing your MMSI, position, and nature of distress to all DSC-equipped stations

Answer

Pressing and holding the distress button transmits a DSC distress alert on Channel 70 to all stations. The alert includes your MMSI, position (from GPS), time, and nature of distress if programmed.

Question 5

After sending a DSC distress alert, what should the operator do next?

Accepted Answer

Switch to Channel 16 and broadcast a Mayday voice message to provide full details of the distress

Answer

After the DSC alert on Ch70, the radio should switch to Channel 16 where the operator must make a full Mayday voice call providing complete details including position, nature of distress, and assistance required.

RYA SRC Practice Test

RYA SRC Practice Test

RYA SRC DSC Operations