Automatic Identification Systems (AIS)
What is AIS?
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 provides information that is critical for sanctions screening and maritime domain awareness.
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.
Understanding the Basics: Important AIS-Related Terms
| Term | Definition |
| Automatic Identification System (AIS) | A tracking system used on ships and by vessel traffic services to identify and locate vessels |
| Transponder | A device that automatically transmits and receives AIS data on vessels |
| Maritime Mobile Service Identity (MMSI) | A unique identification number assigned to each AIS-equipped vessel |
| IMO Number | A unique identification number assigned to ships for maritime safety and pollution prevention |
| Very High Frequency (VHF) | The radio frequency range used by AIS for transmitting data |
| Electronic Chart Display and Information System (ECDIS) | A navigation information system integrating AIS data for mariners |
| Class A Transponder | AIS transponder used on commercial vessels, providing high transmission power and frequent updates |
| Class B Transponder | AIS transponder used on smaller vessels, with lower transmission power and less frequent updates |
| Static Data | Information that does not change, such as vessel name, MMSI, and dimensions |
| Dynamic Data | Real-time information like vessel position, speed, and course |
| Voyage-Related Data | Data including destination, ETA, and draught, entered manually and updated as needed |
| Vessel Traffic Services (VTS) | Services provided by shore-based stations to monitor and manage vessel traffic |
| Satellite AIS (S-AIS) | Extension of AIS using satellites to receive AIS signals globally |
| Collision Avoidance | The primary purpose of AIS, helping to prevent collisions by providing real-time vessel data |
3 Key Components of AIS:
- Transponder: each AIS-equipped vessel has a transponder that automatically transmits and receives data
- Shore-based stations: these stations receive AIS data from ships within their range and can also transmit information
- Satellites: AIS data can also be received by satellites, extending coverage beyond the terrestrial range
Five Benefits of AIS
- Collision avoidance: by providing real-time information about nearby vessels, AIS helps prevent collisions, especially in congested areas and during poor visibility conditions
- Traffic management: AIS allows port authorities and VTS to monitor and manage vessel traffic more efficiently
- Search and rescue: AIS assists in locating vessels in distress, facilitating quicker and more accurate search and rescue operations
- Operational efficiency: AIS data helps shipping companies optimize routes and improve operational efficiency
- Maritime security: AIS aids in monitoring vessel movements, enhancing security and compliance with regulations
Brief History of AIS
- Global implementation: by the early 2000s, AIS transponders were being installed on a wide range of vessels, from large commercial ships to smaller fishing and recreational boats. Shore-based AIS stations were also established in major ports and along coastlines
- Integration with navigation systems: AIS data was integrated with Electronic Chart Display and Information Systems (ECDIS) and other navigational aids, providing mariners with real-time information on vessel movements
- Satellite AIS: Satellite AIS (S-AIS) was launched to extend the range of AIS beyond the line-of-sight limitations of VHF radio, and satellite AIS was developed. The first S-AIS systems were launched in the mid-2000s, allowing for global coverage of AIS signals
- Enhanced monitoring: satellite AIS significantly improved the ability to monitor vessel movements in remote and open ocean areas, contributing to enhanced maritime safety and security
Recent Developments:
- Technological enhancements: continued advancements in AIS technology have led to more sophisticated transponders, better data accuracy, and integration with other maritime information systems
- Expansion of use cases: AIS is now used for a variety of applications beyond collision avoidance, including environmental monitoring, search and rescue, and maritime domain awareness.
- Data analytics: the vast amount of AIS data generated is being used for big data analytics, helping to identify trends, optimize shipping routes, and improve port operations.
The Significance of AIS and Deceptive Shipping Practices
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).
According to the U.S. Departments of the Treasury’s Office of Foreign Assets Control (OFAC) advisory, it’s known as deceptive shipping practices when bad actors seek to exploit global supply chains for their benefit. “This advisory reflects the U.S. government’s commitment to work with the private sector to prevent sanctions evasion, smuggling, criminal activity, facilitation of terrorist activities, and proliferation of weapons of mass destruction (WMD), with a focus on Iran, North Korea, and Syria.”
Examples of AIS-Related Deceptive Shipping Practices
- Disabling or manipulating the AIS: vessels engaged in illicit activities sometimes intentionally disabled AIS transponders or manipulated data transmitted to mask movements.
- Identity tampering: the deliberate falsification of a vessel’s broadcasted data on AIS and/or alterations to its physical features, to misrepresent its identity.
- Dual transmission: the use of multiple AIS transmitters onboard a single vessel transmitting different entities with separate IMO numbers.
- AIS gaps: these are periods in time when an AIS transponder stops emitting signals. It may or may not indicate dark activity (depending on whether the gap is intentional or not).
What is AIS Spoofing?
AIS spoofing involves the intentional alteration of Automatic Identification System (AIS) data to mislead maritime vessels or monitoring systems. Spoofers can create hazardous situations by broadcasting false information, such as changing a vessel’s identity, position, or speed.
In recent years, bad actors have become more sophisticated and developed new methods to conceal their illegal activities. AIS spoofing has become a broad term encompassing three primary deceptive shipping practices:
1. AIS handshake: this involves using a decoy vessel as a disguise. While sailing in close proximity, the “dirty” vessel assumes the identity of the “clean” vessel, allowing the clean vessel to reach its destination undetected. Upon returning, the vessels switch identities again, leaving the clean vessel unscathed.
2. Zombie vessel: this practice uses the identity of a scrapped vessel to conduct illicit operations without facing legal consequences.
3. Location (GNSS) manipulation: This involves using machine-generated locations or paths to mask the true location of the vessel. Various methods can be used to execute this deception, including false transmissions from onboard the vessel and third-party onshore accomplices.
These sophisticated spoofing techniques highlight the need for advanced monitoring and detection systems to safeguard maritime operations.
