Vessels of interest in Finnish AIS

How to read this page

Read with care. A listing is a government designation, quoted as published; it is not a finding by this project, and the map does not say what any ship is doing. AIS positions come from each ship's own GNSS receiver and can be jammed, spoofed or falsified, so a position here is what the ship reported, not where it was seen. Reports that failed the spoofing tests are left out of positions and tracks and counted instead.

Ships on official sanctions lists, ships declaring military or law-enforcement work, and Russian, Chinese, Iranian and North Korean-flagged commercial and state ships, as heard by Finland's shore AIS stations. For each ship: the identifiers it broadcasts about itself, any official listing, where it last reported, how regularly it reported, and how many of its reports failed the spoofing tests. Metadata only: no communications content.

• Sanctioned means the IMO number the ship broadcasts is on the US Treasury OFAC SDN List or the UK Sanctions List, worded as each list publishes it: "listed by OFAC on date under programme". OFAC's date is the day the entry was published on the SDN List. A listed MMSI counts as a match only when the ship broadcasts no valid IMO number, and is marked as unconfirmed. A matching name alone never puts a ship on the map.
• Military and law enforcement are AIS ship types 35 and 55, as the ship declares them. Many state ships switch AIS off or declare another type, so their absence here means nothing.
• State flags of interest come from the first three digits of the MMSI (the Maritime Identification Digits): Russia 273, China 412–414, Iran 422, North Korea 445. That is the flag the transponder claims, which can differ from the registry. Only cargo ships, tankers, tugs, passenger ships, service craft and state types are shown; fishing boats, sailing yachts and pleasure craft never are.
• Failed spoofing tests counts reports that needed an impossible speed from the ship's last trusted position, reported an impossible speed over ground, or put the ship 20 km or more inland. They usually mean the ship's GNSS receiver was jammed or spoofed, which in the eastern Gulf of Finland happens to many ships at once. They can also come from a faulty transponder or two ships sharing one MMSI.
• Gaps over 1 hour leave out the hours when our collector was down. A gap can mean the ship left the coverage of the Finnish stations, entered a port the stations don't hear, or switched AIS off; the data can't tell these apart.
• Owners are the companies the lists themselves name: OFAC's "owned or controlled by" and "property in the interest of" links, and the UK list's current owner/operator. A company's country is its address on the SDN or UK list; for a UK-named company it is found only when the same name is itself designated with an address, so many have none. People linked to ships are never shown. Commercial registries (and Equasis, whose terms forbid reuse) are not used.
• Believed flag is the flag the UK list believes the ship now flies, which can differ from the flag its MMSI claims.
• Sea zone is the Marine Regions zone (internal waters, then EEZ) holding the last trusted position. Zone limits there are those of the Marine Regions database, which is a research product, not a legal statement.
• Destination is read from the text the crew types, when it is a UN/LOCODE ("RUULU", "RU ULU"), a code after an arrow ("FIHEL>EETLL") or a port name in the World Port Index. Ports and their codes come from the World Port Index; a code it lacks still gives the country. "FOR ORDERS" and similar stay unread.
• Port calls are stops of an hour or more under 1 knot within 10 km of a World Port Index port, from the trusted positions in this data. Anchorages far from a listed port don't count. Home port (port of registry) is not in any open source we can use, so it is never shown.
• Signals are what the ship broadcasts about itself: class (Class A is inferred when the ship sends voyage data that only Class A transponders send), destination and ETA as typed by the crew, draught, size from the antenna offsets, and the position source the transponder declares (GPS, GLONASS, Galileo, combined and so on), which is a setting, not a check of what the receiver uses. "IMO check digit" says whether the broadcast IMO number is internally valid.
• Satellite imagery on this map is Copernicus data served by Microsoft Planetary Computer, from zoom 10: Sentinel-2 at 10 m, one mosaic per month with the clearest scenes drawn first (it shows places such as ports and terminals, and a cloudy month shows cloud), and Sentinel-1 radar, the latest pass in the period drawn first, which sees through cloud and shows ships as bright points at the time of that pass, whether or not they broadcast AIS. The panel gives the date of the image at the map centre. The links in a ship's panel open other providers' own viewers at its last trusted position: Google Maps and Esri Wayback for sharper imagery (Wayback keeps versions back to 2014), and Copernicus Browser and NASA Worldview for imagery near that date. Where it is offered, Esri World Imagery adds sharp current imagery (about 15 cm to 1.2 m); it is not offered in places Esri's terms exclude (see the terms of use), and it stops if the site's free monthly allowance runs out.
• Times are UTC, with your own time zone alongside (change it with the Time button).

Data: Digitraffic AIS from Fintraffic. Source: Fintraffic / digitraffic.fi, license CC 4.0 BY. Sanctions: US Treasury OFAC SDN List (US government work) and the UK Sanctions List; contains public sector information licensed under the Open Government Licence v3.0. Sea zones: Flanders Marine Institute (2023), Maritime Boundaries Geodatabase, World EEZ v12 and Internal Waters v4, marineregions.org, CC BY 4.0 (only the zone of each ship's position is published, not the boundaries). Ports: NGA World Port Index (US government). Land and borders: Natural Earth (public domain). The data is refreshed by hand, not daily: python tools/sanctions.py then python tools/vessels_build.py (code).