Automatic identification system (AIS) transponders transmit a ship’s position, identification number, and accompanying details about the ship. AIS maritime transponders broadcast static, dynamic, and voyage information. This information – destination, type of ship, International Maritime Organization (IMO) number, etc. – can be manually updated by a ship’s crew, or viewed and stored digitally. AIS provide information that is critical for sanctions screening and maritime domain awareness.
What is AIS?
AIS technology complements a vessel’s radar and enables ship captains and crew to understand if other ships are in the area, and then maintain a safe distance. There are different types of AIS transmissions, but all contain the ship’s location and speed, plus vessel identifiers and voyage information.
The maritime ecosystem has increasingly comprehended the richness of the generated data for a multitude of applications:
- Accident investigation
- Maritime security
- Search and rescue
- Operational planning
- Fishing fleet security
- Trade analysis
Shipping companies, freight forwarders, oil and energy companies, insurers, law enforcement and homeland security teams, commodity traders, and financial organizations utilize AIS navigation data for enhanced risk management and marine domain awareness.
Brief IMO & AIS History
The IMO adopted a resolution in 1987 to assign a unique and permanent identification (ID) number to every ship for its entire lifespan. The IMO number consists of three letters –”IMO” – followed by a seven-digit number. This number remains static, even if the vessel’s owners, flag(s), or name are altered. Since 1996, management companies, ships, and registered ship owners have received these identifiers under the International Convention for the Safety of Life at Sea (SOLAS).
AIS ship tracking systems were developed in the 1990s primarily for safety and collision avoidance. They were particularly useful at night, or when visibility was lacking due to adverse weather conditions. The IMO made changes to SOLAS in 2000 that took effect in 2002. The amended SOLAS treaty stipulated that commercial vessels and passenger ships over 300 gross tons (GT) are required to carry Class-A AIS transceivers. Passenger ships must also display the IMO marking on an aerial-facing surface since 2004.
AIS is the main method for tracking ships, especially since the introduction of commercial satellites, which enable global tracking.
The Significance of AIS & “Dark Activity”
The Russia-Ukraine conflict reminded everyone that vessel owners or captains may choose to disable their AIS for certain periods, which is referred to as “dark activity,” to avoid being caught evading sanctions on an AIS map by visiting prohibited ports, or engaging in illicit ship-to-ship (STS) cargo transfers (smuggling).
Five major maritime issues globally:
- Human trafficking
- Border breaches
- Illegal fishing practices
Important AIS Note
The majority of AIS transmission gaps worldwide are unintentional. Common reasons for gaps include:
- Poor coverage (think of cell phone coverage)
- Stormy weather conditions
- GPS jamming by bad actors or the authorities
- Signal collision caused by overcrowded areas.
The ability to weed out “false positive” alerts generated by accidental AIS transmission gaps is critical.