Sanctioned ships on the map: what the list is and what it does not say
The map can mark ships on the US sanctions list. Here is how the match is made, and what it does not mean.
Kartradar can mark ships that are on the US sanctions list. The layer is off by default and can be turned on under "More layers" in the menu. Here is what the list is, how a ship ends up marked as listed on the map, and, just as importantly, what the marking does not say.
Which list
The list is the "Specially Designated Nationals and Blocked Persons" list (SDN), published by OFAC, the sanctions office of the US Treasury. It contains people, companies and vessels that US citizens and companies may not deal with. Vessels are listed with name, flag, type and IMO number, and the sanctions programme they are listed under.
Kartradar downloads the list every day. In October 2026 it contained 1524 vessels with an IMO number.
How a ship is marked
The match is made on the IMO number, not the name or the radio identity. The IMO number follows the hull for its whole life and does not change when the ship is renamed, sold or reflagged. The radio identity (MMSI), on the other hand, follows the flag state and changes with every change of flag, which is exactly what vessels on such lists often do. That is why sanctions lists use the IMO number.
Ships send their IMO number in separate AIS messages. If the number is on the list, the ship is marked on the map, and the panel shows which programme it is listed under, the date of the list, and a link to the entry at OFAC.
When we checked on a Monday afternoon in October 2026, one listed vessel was visible in Norwegian waters: ZALIV VOSTOK, listed under the programmes RUSSIA-EO14024 and UKRAINE-EO13662.
What the marking does not say
This is the most important section.
- It is a reproduction, not an assessment. Kartradar does not flag any ship on its own judgement. The marking only means the IMO number is on the official list.
- It says nothing about what the ship is doing now. A listed ship may be lawfully in transit, and a ship that is not marked may be covered by other countries' sanctions.
- It is only the US list. The EU and the UK have their own lists. The EU's machine-readable list only contains asset-freeze decisions, while its vessels are listed in an annex published as PDF. The UK's ship list is outside the open file. Neither is included today.
- The term "shadow fleet" is not used. It is a characterisation, not something the source states.
Why many ships cannot be checked
Only about half of the ships in Nordic waters provide an IMO number. The rest are mostly fishing boats and smaller vessels that do not have one. They can neither be marked nor ruled out.
A ship is also only shown when it transmits AIS itself, and vessels in this category often switch it off. If a listed ship stands still or disappears from the map, it may just as well be because the signal is gone as because the ship is. Why ships stand still or disappear is explained here.
How to use the layer
- Open the menu and turn on "Sanctioned vessels (OFAC)" under "More layers".
- Listed ships are marked on the map.
- Tap a marked ship to see the programme, list date and link to OFAC.
More about the sources and limitations is on the sources page.