Marine VHF Radio is a worldwide system of two way radio transceivers on ships and watercraft used for bidirectional voice communication from ship-to-ship, ship-to-shore (for example with harbormasters), and in certain circumstances ship-to-aircraft.
Marine VHF radio refers to the radio frequency range between 156.0 and 162.025 MHz, In the official language of the International Telecommunication Union the band is called the VHF maritime mobile band.
Marine radio equipment is installed on all large ships and most seagoing small craft.
A marine VHF set is a combined transmitter and receiver and only operates on standard, international frequencies known as channels. Channel 16 (156.8 MHz) is the international calling and distress channel.