Risk & markets
AIS (Automatic Identification System)
A transponder system that broadcasts a ship's identity, position and course.
What is AIS (Automatic Identification System) in shipping?
A VHF-based system that continuously transmits a vessel's MMSI identity, position, speed and heading to nearby ships and shore stations for collision avoidance and traffic management. Because the signal is open, AIS also underpins commercial vessel-tracking — which is why 'going dark' (switching it off) is a red flag for sanctions evasion.
Educational reference only — verify operational guidance with UKMTO, MSCHOA, your flag state, P&I club and legal counsel.
Related terms
- Dark fleet (shadow fleet) — Aging tankers that obscure ownership and switch off tracking to move sanctioned cargo.
- Chokepoint — A narrow, strategically critical stretch of water that concentrates global shipping.
- Sanctions / SDN list — Government measures restricting dealings with named entities, vessels or cargoes.