Documentation · Risks

Maritime risk and the shadow fleet

Ships carry most of the world's traded oil, metals and goods, and sanctioned trade hides easily at sea. This guide explains the risk in plain language, the signs that a vessel or counterparty is concealing its activity, what Canadian, US, UK and EU authorities expect, and how to screen vessels by IMO number on Crown Intelligence.

What the risk is

The “shadow fleet” is a term for aging tankers and other ships that operate with opaque ownership, unclear insurance and flag arrangements, and deliberate concealment, so that sanctioned oil or goods can still be moved and sold. The US Treasury describes Iran's shadow fleet as generally made up of older, poorly maintained vessels that operate outside standard maritime regulations [3]. Canada describes Russia's shadow fleet in the same way, as mostly oil tankers used to transport sanctioned goods and commodities, including crude oil [5]. Canada reports having sanctioned more than 600 vessels on that basis [5].

For a business, the risk is that a payment, insurance policy, charter, port call, bunkering arrangement or cargo finance deal ends up supporting a sanctioned party, even where the business never meant to deal with one. The Financial Action Task Force (FATF) lists “exploiting the maritime and shipping sectors” as one of four major typologies used to evade sanctions [1].

How it shows up: red flags and typologies

No single sign proves evasion. Treat the following as reasons to ask questions and document the answers, and combine several before deciding.

  • AIS gaps and manipulation. A vessel switches off its automatic identification system (AIS) or alters its data. OFAC notes ships that broadcast the MMSI number of a different vessel, or the IMO number of a ship that has been scrapped [3]. Extended silence in high-risk waters should trigger enhanced due diligence [3].
  • Successive ship-to-ship (STS) transfers. Cargo moved between ships several times. OFAC says Iranian tankers often use three to five transfers in one shipment, and that successive transfers at night, in unsafe waters or near sanctioned jurisdictions are a strong risk factor [3].
  • Flag hopping. Frequent changes of registration. OFAC cites three flag changes within a year as a reason to ask for ownership, voyage and flag history, and flags a vessel that claims a “false” or “unknown” flag [3].
  • Identity swaps. A name, IMO or MMSI number that appears in conflicting records, or sister vessels with similar names and histories. OFAC advises researching each vessel in a chain of transfers by name and by several identifiers, not by name alone [3].
  • Opaque ownership. Single-ship companies or special-purpose vehicles in low-transparency jurisdictions, owners with no public profile, and brokers that move vessels to new shell companies [3].
  • Weak or unknown insurance. New or untested insurers, no insurance evidence, or cover from a provider linked to sanctioned parties [3].
  • Altered documents. Bills of lading, certificates of origin or last-port-of-call records that have been changed or reissued. OFAC says any sign of manipulated shipping documentation should be investigated before a transaction continues [3].
  • Cargo origin. Certificates of origin issued in jurisdictions known for obscuring Iranian origin, and frequent STS activity in nearby waters. OFAC names Oman, the United Arab Emirates and Iraq for certificates, and Malaysia and Singapore for STS activity [3].
  • Substandard vessels and port tolerance. Old tankers that call at ports which overlook port-state control inspections, or that receive bunkering, flagging or crew services from providers serving other shadow fleet tankers [3].

Why the IMO number matters

The IMO number is the most reliable identifier for a ship. It is seven digits prefixed with the letters “IMO”, it stays with the ship for its whole life even if its flag, name, ownership or type changes, and numbers from ships no longer in service are not reallocated [4]. The number is marked on the hull and carried in ship certificates [4]. Companies and registered owners have their own IMO numbers [4].

The IMO number is still not a complete check. Names and flags change, and AIS can carry another ship's identity [3]. Screen by IMO number first, and fall back to name and aliases only where no IMO number exists. Our maritime collection does not yet record MMSI numbers or flag-state history, so flag-hopping and AIS checks need a vessel-tracking source and the public registries listed in the sources below.

What regulators expect

Canada

  • Sanctions. Canada's Russia measures are made under the Special Economic Measures Act and the Special Economic Measures (Russia) Regulations [7][6]. On 26 March 2026 Canada added 100 more shadow fleet vessels to its sanctions list [5]. Canada also prohibits the import of Russian crude oil, refined petroleum products and gaseous hydrocarbons [8].
  • Anti-money laundering and reporting. The Proceeds of Crime (Money Laundering) and Terrorist Financing Act governs reporting entities, and the Suspicious Transaction Reporting Regulations set out the reporting duty [9]. FINTRAC is Canada's financial intelligence unit and anti-money laundering and anti-terrorist financing supervisor [11]. Its operational alerts and money laundering and terrorist financing indicators are the reference points for what to report [10].
  • Port state control. Transport Canada runs an inspection program for non-Canadian commercial vessels [17].

United States

OFAC's April 2025 advisory sets out what it expects from shipping, insurance, port and financial stakeholders. The points include knowing the vessel (IMO number, ownership, operators and voyage history), verifying cargo origin and insurance, verifying flag, monitoring for AIS manipulation, including sanctions exclusion and termination clauses in contracts, and refusing service to sanctioned vessels [3]. OFAC reports that between December 2024 and April 2025 it sanctioned 86 individuals and entities in more than 25 countries and identified 85 tankers as blocked property [3].

United Kingdom

The Office of Financial Sanctions Implementation (OFSI) publishes industry guidance on the UK Maritime Services Ban and the oil price cap exception [12]. UK sanctions legislation gives government and maritime enforcement officers powers to detain vessels, prevent port entry, and stop, board and search ships suspected of sanctions violations [13].

European Union

EU restrictions on Russia are set out in Council Regulation (EU) No 833/2014 [14]. Check the current consolidated text for its vessel and maritime-service provisions before relying on any list, because the measures change often.

FATF and port-state control

FATF's June 2025 report found that only 16% of the countries it assessed had high or substantial effectiveness in targeted financial sanctions for proliferation financing [1]. It recommends public-private information sharing and detailed alerts to help institutions file suspicious activity and transaction reports [1]. In port-state control, the Paris MoU publishes ships currently held in port after inspectors found deficiencies serious enough to prevent safe sailing, and the EMSA THETIS database calculates each ship's risk profile daily [15][16].

How to screen with Crown Intelligence

The maritime collection holds vessels, owners and operators on sanctions lists and port-ban lists, with IMO numbers where the publisher gives one. It answers the question “is this vessel or party on a list we hold?” It does not show where a ship is now, its AIS history or its flag history.

Live figures (fetched when this page loads):

  • Maritime collection: … records from … sources.
  • Consolidated sanctions: 350,348 records.
  • Figures as of September 24, 2026.

Where to look:

Limits: the maritime collection does not yet record MMSI numbers or flag-state history, and Crown Intelligence does not hold live AIS positions or cargo-tracking data. Use a vessel-tracking source for those checks, and the registries in the sources below.

Checklist for a vessel transaction

  • Record the IMO number of every vessel in the transaction, and confirm that it is seven digits after “IMO” [4].
  • Screen the vessel, its registered owner, operator, manager and beneficial owners, not only the ship's name [3].
  • Compare names and aliases against the IMO number, and record any mismatch.
  • Check flag history and registry status, including the IMO GISIS database for false or unknown flags [3].
  • Ask for AIS and ship-to-ship transfer history for voyages in high-risk waters [3].
  • Request certificates of origin and the full document trail for the cargo [3].
  • Confirm insurance comes from a known insurer, and check the insurer's sanctions status [3].
  • Check port-state detentions for the vessel in the Paris MoU and THETIS records [15][16].
  • Include sanctions exclusion and termination clauses in charters, insurance and service contracts [3].
  • Record the checks and the decision with a date, escalate suspicion to your anti-money laundering officer, and file a suspicious transaction report where Canadian reporting duties apply [9].

Frequently asked questions

Is a vessel's name enough to screen it?

No. Names change, and AIS can carry the identity of another ship. Check the IMO number and other identifiers [3]. The IMO number stays with the ship through name and flag changes [4].

Does a match mean the ship is blocked?

A match means a record needs review. Confirm the identifiers and the sanctions program or list on the record, then decide what to do under your own policy and the law that applies to you. A match is not a legal determination.

Can an AIS gap alone prove sanctions evasion?

No. OFAC treats AIS manipulation as one indicator to investigate, alongside other signs and enhanced due diligence [3]. Some AIS disablement is for safety, and OFAC says the circumstances should be documented [3].

What is the difference between a sanctions listing and a port detention?

A sanctions listing is a government designation. A port-state detention follows an inspection in which deficiencies were found that are serious enough to stop the ship sailing safely [15]. A detention is a safety and compliance signal, not a sanctions finding, but it can support a risk review.

Does Crown Intelligence show where a ship is now?

No. The maritime collection holds listings and IMO numbers from official sources. Live positions, AIS history and cargo tracking need a vessel-tracking source.

Sources

Each source was read or checked on 2026-10-10 unless noted. Links open the publisher's page.

  1. FATF, FATF Report highlights major gaps in global response to Proliferation Financing and Sanctions Evasion, press release, 20 June 2025. fatf-gafi.org
  2. FATF, Complex Proliferation Financing and Sanctions Evasion Schemes, June 2025 (report). fatf-gafi.org (PDF)
  3. US Department of the Treasury, OFAC, Sanctions Advisory: Guidance for Shipping and Maritime Stakeholders on Detecting and Mitigating Iranian Oil Sanctions Evasion, 16 April 2025. ofac.treasury.gov (PDF)
  4. International Maritime Organization, IMO Identification Number Scheme, web page. imo.org
  5. Global Affairs Canada, Minister Anand announces additional sanctions against Russia, news release, 26 March 2026. canada.ca
  6. Justice Laws Website, Special Economic Measures (Russia) Regulations, SOR/2014-58. laws-lois.justice.gc.ca
  7. Global Affairs Canada, Canadian sanctions related to Russia, web page. international.gc.ca
  8. Canada Gazette, Part II, Volume 160, Number 7, regulations registered 8 April 2026, including the Special Economic Measures (Russia) Regulations amendment. gazette.gc.ca
  9. Justice Laws Website, Proceeds of Crime (Money Laundering) and Terrorist Financing Act, S.C. 2000, c. 17, current to 21 September 2026. laws-lois.justice.gc.ca
  10. FINTRAC, Money laundering and terrorist financing indicators and Operational alerts, guidance pages. fintrac-canafe.canada.ca (indicators); fintrac-canafe.canada.ca (alerts)
  11. Government of Canada, Financial Transactions and Reports Analysis Centre of Canada, organization page. canada.ca
  12. HM Treasury, Office of Financial Sanctions Implementation, UK Maritime Services Ban and Oil Price Cap: industry guidance. gov.uk
  13. House of Commons Library, Seizing the shadow fleet, research briefing. commonslibrary.parliament.uk
  14. Council Regulation (EU) No 833/2014 of 31 July 2014 concerning restrictive measures in view of Russia's actions destabilising the situation in Ukraine, consolidated text. eur-lex.europa.eu
  15. Paris MoU, Detentions, current detentions page. parismou.org
  16. Paris MoU, Inspection Search (THETIS), page describing the European Maritime Safety Agency database. parismou.org
  17. Transport Canada, Inspection of non-Canadian commercial vessels, web page. tc.canada.ca

Crown Intelligence collection pages and live figures come from our own site and API; see the maritime collection page.

This guide is general information from public sources, not legal, financial or compliance advice. Sanctions and reporting duties depend on the facts of each transaction and on the laws that apply to you. Speak with a qualified adviser before you act on any screening result.

Last updated 2026-10-10