What is the primary use of VHF channel 16?

The primary use of VHF channel 16 encompasses distress, urgency, brief safety communications, and calling. This channel is designated as the international distress frequency for vessels and is used globally to ensure that ships can communicate emergencies effectively.

When a vessel is facing a distress situation, it can transmit a Mayday call on this channel to alert other ships and the coastal stations of its plight, allowing for rapid response and assistance. Additionally, the channel is used for urgency messages that may not necessitate a full distress situation but still require immediate attention, such as a vessel reporting a fire on board or a person overboard.

Also, it serves as a calling frequency, allowing vessels to initiate contact with one another before switching to a working channel for further communication. This dual role of distress signaling and facilitating communication makes channel 16 a vital component of maritime safety.

The other options, which focus on either commercial communications or routine port communications, do not capture the comprehensive nature of its use in emergency situations and urgent communications, which are critical for ensuring safety at sea.