VHF
VHF (Very High Frequency) marine radio is a SOLAS-mandated communication system and a core component of GMDSS.
It is used for short-range distress, safety, and routine communications, including ship-to-ship and ship-to-shore contact, using voice and Digital Selective Calling (DSC).
Is VHF mandatory under SOLAS?
Yes. VHF radio is mandatory under SOLAS Chapter IV for all passenger ships and cargo ships of 300 GT and above on international voyages.
What is the main purpose of marine VHF?
VHF enables immediate communication for:
Distress, urgency, and safety messages
Navigational coordination
Port and pilot communications
Collision avoidance
Is VHF part of GMDSS?
Yes. VHF is a primary GMDSS system for ships operating in Sea Areas A1 and A2.
What is DSC in VHF?
Digital Selective Calling (DSC) allows automated distress alerts to be sent with the vessel’s identity and position by pressing a single button.
Which channel is used for distress and safety?
Channel 16 – Distress, urgency, and safety voice communications
Channel 70 – DSC distress and calling (no voice traffic)
What is the typical range of VHF radio?
VHF range is usually 20–30 nautical miles, depending on antenna height and atmospheric conditions.
Does VHF require continuous watch?
Yes. A continuous watch on Channel 16 and DSC Channel 70 must be maintained, as required by SOLAS.
Can VHF be used for routine communications?
Yes. VHF is commonly used for routine operational communications, including bridge-to-bridge and port authority contact.
Is VHF testing and maintenance required?
Yes. VHF radios must be regularly tested, logged, and maintained, including checks of DSC functionality and antenna condition.
Is VHF inspected during surveys?
Yes. Flag and Port State inspectors verify DSC distress operation, power supply, antenna installation, channel selection, and radio logs.
Conclusion
VHF radio is a fundamental SOLAS-mandated GMDSS communication system that ensures immediate and reliable short-range communication for distress, safety, and routine operations. As the primary means of communication in coastal and port waters, VHF plays a crucial role in collision avoidance, emergency response, and day-to-day vessel coordination.
Maintaining a fully operational VHF system, with continuous watch, regular testing, and proper documentation, is essential for IMO compliance and successful flag and port State inspections.