Which VHF channel is used only for digital selective calling?

Channel 70 is designated exclusively for digital selective calling (DSC) in the VHF band. DSC is a crucial part of marine communication, enabling vessels to send a distress signal without the need for voice communication, thereby ensuring a quick and effective response. This channel operates at 156.525 MHz, and its exclusive use for DSC means it is only intended for automated distress alerts and safety communications, which enhances safety and efficiency in maritime operations.

In contrast, other channels mentioned serve multiple purposes. Channel 16 is primarily used for distress calls and hailing, while Channel 22A is often used for maritime safety information and communications. Channel 6, on the other hand, is used for intership communication related to navigation and safety, making it unsuitable for the specific function of DSC. Thus, Channel 70's unique purpose underscores its importance in facilitating timely maritime distress signaling.