RYA SRC DSC Procedures 1 — Questions and Answers
Question 1: What does DSC stand for in VHF marine radio?
- Digital Selective Calling (Correct answer)
- Direct Signal Communication
- Distress Signal Code
- Digital Safety Channel
Correct answer: Digital Selective Calling
DSC stands for Digital Selective Calling, a system that allows automated distress alerts and vessel-to-vessel calling using digital signals on VHF radio.
Question 2: Which VHF channel is used exclusively for DSC distress alerting?
- Channel 70 (Correct answer)
- Channel 16
- Channel 67
- Channel 06
Correct answer: Channel 70
Channel 70 is reserved exclusively for DSC distress alerting and calling. It must never be used for voice communications.
Question 3: What information is automatically included in a DSC distress alert?
- MMSI number, nature of distress, and vessel position if GPS-linked (Correct answer)
- Vessel name, port of registry, and crew list
- Owner's contact details and insurance information
- Departure port, destination, and ETA
Correct answer: MMSI number, nature of distress, and vessel position if GPS-linked
A DSC distress alert automatically transmits the vessel's MMSI number, the nature of distress (if selected), and position with time if the radio is connected to a GPS.
Question 4: After sending a DSC distress alert, what must you do immediately?
- Switch to Channel 16 and transmit a MAYDAY voice call (Correct answer)
- Wait silently on Channel 70 for acknowledgement
- Send a second DSC alert on Channel 16
- Switch off the radio to preserve battery power
Correct answer: Switch to Channel 16 and transmit a MAYDAY voice call
After transmitting a DSC distress alert on Channel 70, you must immediately switch to Channel 16 and transmit a MAYDAY voice message to provide further details to rescuers.
Question 5: How often should a DSC distress alert be repeated if no acknowledgement is received?
- After 3.5 to 4.5 minutes (Correct answer)
- After 30 seconds
- After 10 minutes
- After 1 hour
Correct answer: After 3.5 to 4.5 minutes
If no acknowledgement is received, the DSC distress alert should be repeated after 3.5 to 4.5 minutes to allow time for coast stations to respond without causing excessive interference.
Question 6: What is a DSC individual call used for?
- Calling a specific vessel or coast station by their MMSI number (Correct answer)
- Broadcasting to all vessels in the area
- Sending a distress alert to the coastguard
- Testing the DSC controller
Correct answer: Calling a specific vessel or coast station by their MMSI number
A DSC individual call allows you to contact a specific vessel or coast station directly by entering their unique MMSI number, similar to dialling a telephone number.
RYA SRC DSC Procedures 1
What does DSC stand for in VHF marine radio?