What is DSC on a VHF radio used for?

• A. Digital Select Calling to quickly contact a specific vessel or shore station in an emergency.
• B. Providing GPS coordinates.
• C. Receiving weather alerts only.
• D. Transmitting continuous audio.

Answer: (A)

Digital Select Calling is a digital way to reach a specific vessel or shore station quickly, especially in an emergency. It lets you pre-program the MMSI (the unique identification number for boats and stations) so you can trigger a call that automatically goes to the intended recipient, often with a distress, urgency, or safety priority. This speeds up contact when time matters and helps avoid tuning to the right channel and hoping someone is listening.

The system is part of the Global Maritime Distress and Safety System, designed to improve how alerts and contact are made at sea. While a DSC call can carry data like your position if your GPS is connected, its primary purpose is to establish contact, not to provide GPS coordinates as the main function. It isn’t used for receiving weather alerts as its main role; weather information typically comes over dedicated weather channels or data broadcasts. And it isn’t about transmitting continuous audio—that would be a regular voice call.