When arriving in a port, complementary to her AIS signal (encoded VHF message) it seems that the vessel also has to emit a voice message on a predifined VHF frequency to identify herself as part of the VTS process (Vessel Tracking System).
Is it something codified for all ports ? Which information are given ? only name/imo/callsign ? destination berth ?cargo on board ? Is it legal to listen to those messages ? Specifically for the US ?