(WASHINGTON) — A very high frequency (VHF) maritime radio transmission on one’s own vessel, or even transmissions by a nearby vessel a football field’s length away (about 445 feet), may block AIS reception for the duration the radio is keyed.
An analysis of the relevant standards has shown that this may impact all classes of AIS equipment regardless of how the antennas for the two systems are installed.
Antennas installed in conformance with the International Maritime Organization’s (IMO) COMSAR.1/Circ. 32/Rev. 2 “Harmonization of GMDSS Requirements for Radio Installations On Board SOLAS Ships,” IMO SN.1/Circ. 227 “Guidelines for the Installation of a Shipborne Automatic Identification System,” or the National Marine Electronics Association (NMEA) Installation Standard 0400 per 33 CFR 164.46(a), while helpful, will not avoid