🔍 Key Concepts

• Digital Selective Calling (DSC) purpose and how distress alerts are sent • What Channel 70 is reserved for in the VHF marine band • The relationship between a DSC distress alert and follow‑up MAYDAY voice traffic

💭 Think About

• Ask yourself: Which VHF channel is specifically designated for DSC signaling, and is it used for voice or for digital alerts? • Consider: When you press the DSC distress button, does the radio immediately transmit your MAYDAY voice message, or does it first send a digital alert on a dedicated channel? • Think about: After a DSC distress alert is sent, on what channel is the follow‑up MAYDAY voice communication normally conducted?

✅ Before You Answer

• Verify which channel (Ch-70) is reserved internationally for DSC only, no voice • Check whether a DSC distress alert is required to be transmitted simultaneously on Ch-16 as part of the digital signal, or if Ch-16 is mainly for the subsequent voice MAYDAY • Confirm whether any reputable standard allows manufacturers to choose between Ch-70 and Ch-16 for sending the DSC distress alert itself