What is the primary purpose of channel 70 in VHF marine communication?

The primary purpose of channel 70 in VHF marine communication is for Digital Selective Calling (DSC). DSC operates as a system that enables vessels to send and receive automated distress alerts and routine communication with other vessels or shore stations. It allows for the transmission of distress calls with the push of a button, initiating a standardized communication protocol to enhance safety at sea.

Channel 70 is specifically reserved for this purpose and does not support voice communication, which distinguishes it from other VHF channels that are used for general communications or other functions. By utilizing DSC on channel 70, mariners can quickly notify nearby vessels and the coast guard of emergencies, ensuring a faster response time to potential distress situations. This capability has significantly improved the safety and efficiency of marine communications during emergencies.