Electronic Navigation Aids
What is AIS? The automatic identification system, or AIS, transmits a ship’s position so that other ships are aware of its position. The International Maritime Organization and other management bodies require large ships, including many commercial fishing vessels, to broadcast their position with AIS in order to avoid collisions. AIS Class A and Class B Transponders AIS Types. Class A: Mandated for all vessels 300 GT and above engaged on international voyages as well as all passenger ships. Class B: Provides limited functionality and is intended for non-SOLAS vessels. Primarily used for vessels such as pleasure crafts 161.975 MHz AIS operates principally on two dedicated frequencies or VHF channels: AIS 1: Works on 161.975 MHz- Channel 87B (Simplex, for ship to ship) AIS 2: 162.025 MHz- Channel 88B (Duplex for ship to shore) Exchange of short text (safety related) Messages Operates in the VHF maritime band on two designated channels (2250 x 2 slots / min) High capacity - ...