What is AIS ?
AIS (Automatic Identification System) is initially intended to help ships avoid collisions, as well as assisting port authorities to better control sea traffic. AIS transponders on board vessels include a GPS (Global Positioning System) receiver, which collects position and movement details. It includes also a VHF transmitter, which transmits periodically this information on two VHF channels (frequencies 161.975 MHz and 162.025 MHz – old VHF channels 87 & 88) and make this data available to the public domain. Other vessels or base stations are able to receive this information, process it using special software and display vessels locations on a chart plotter or computer.
As of December 2004, the International Maritime Organization (IMO) requires all vessels over 299GT to carry an AIS transponder on board, which transmits their position, speed and course, along with some other static information, such as vessel’s name, dimensions and voyage details.
The US Coast Guard has significantly widened the number of vessels required to operate an AIS. This affects commercial vessels larger than 65 feet as well as certain towing and passenger vessels. The new rules (CFR 164.46) require these vessels to have USCG approved AIS transponders installed by March 2016.
Below is a live map provided by MarineTraffic. MEOB operates a receiving station as part of the AIS network. Those are actual vessels within range of our antenna located here in Nags Head, North Carolina.