| Guide | GDE-001 |
| Topic | Maritime vessel tracking and investigation |
| Domain | Maritime intelligence |
| Last updated | July 2026 |
Short answer: Anchor every query on the IMO number, track the vessel on two independent AIS sources, test each dark period, trace ownership through public registries and screen every name against sanctions lists. The open record did not prove what happened. It proved what could not have happened.
What is maritime OSINT?
Maritime OSINT is the practice of tracking vessels, tracing ownership, and documenting incidents using publicly accessible data, without access to classified or proprietary systems. It covers the full investigative arc from AIS position data through corporate registry research, port inspection records, casualty documentation, and sanctions screening.
When a vessel goes dark in a conflict zone, the AIS gap is not the end of the investigation. It is the beginning. In June 2026, the Ever Lovely transmitted an AIS heading field inconsistent with its stated course in the Strait of Hormuz. Cross-referencing that signal against independent AIS reception and satellite positioning placed the vessel in a coercion corridor before the drone strike was reported. The open record did not prove what happened. It proved what could not have happened, and that is what made it publishable. This guide covers that methodology: from establishing vessel identity through AIS tracking, ownership tracing, port inspection records, incident reconstruction, and sanctions screening.
| • | Tracking a vessel's movements near a conflict zone, sanctioned port, or area of investigative interest. |
| • | Verifying official accounts of a maritime incident against the navigational record. |
| • | Tracing the beneficial owner behind a flag-of-convenience vessel or opaque corporate structure. |
| • | Identifying AIS gaps or spoofing patterns that indicate potential sanctions evasion. |
| • | Documenting ship-to-ship transfers linked to sanctioned cargo or illicit trade networks. |
How to track and investigate a vessel using open sources
The complete workflow: from establishing vessel identity through AIS tracking, ownership tracing, port inspection records, incident reconstruction, and sanctions screening.
The following tools cover the full maritime OSINT workflow. Free tools are listed before paid.
MarineTraffic: Real-time AIS position data and historical voyage playback. Free tier available; extended history and satellite AIS require a paid subscription.
VesselFinder: Independent AIS source for cross-referencing MarineTraffic data. Free tier available. Use alongside MarineTraffic and flag any positional discrepancies.
Equasis: Multi-administration maritime safety registry founded by European maritime administrations, with IMO holding observer status. Links vessels to registered owner, ship manager, flag state, class society, and port state control inspection history. Free with registration.
Global Fishing Watch: Independent AIS reception and gap detection. Free. Particularly useful for identifying dark vessel periods and cross-referencing gaps against MarineTraffic.
OpenCorporates: Corporate registry search for tracing ownership chains across jurisdictions. Free and paid tiers.
ICIJ Offshore Leaks: Searches the Panama Papers, Paradise Papers, Pandora Papers, and related leaked datasets by company and individual name. Free.
OpenSanctions: Cross-references individuals and entities against multiple international sanctions regimes simultaneously. Free.
TankerTrackers: Specialist ship-to-ship transfer tracking with satellite imagery integration. Paid. Relevant for sanctions evasion investigations involving crude oil and petroleum products.