Maritime Sanctions Data
Flag transparency of the OFAC-designated vessel fleet
Data as of 2026-10-15 · source: U.S. Treasury OFAC Specially Designated Nationals (SDN) list
Of 1,506 OFAC-designated vessels with a recorded flag, 47.2% fly a flag-of-convenience / shell-jurisdiction register and only 0.4% fly a flag from a transparent public-UBO register (data as of 2026-10-15).
| Flag-transparency tier | vessels | % of total | |
|---|---|---|---|
| Shell / flag-of-convenience (Tier 3) | 711 | 47.2% | |
| Sanctioned-state flag | 550 | 36.5% | |
| Restricted register (Tier 2) | 188 | 12.5% | |
| Other / unclassified | 51 | 3.4% | |
| Transparent register (Tier 1) | 6 | 0.4% | |
| Total | 1,506 | 100% |
Screen any hull by IMO from code, no key: GET https://arcnautical.com · API docs
Top individual flags
| Flag | vessels | % of total | |
|---|---|---|---|
| Panama | 270 | 17.9% | |
| Russia | 243 | 16.1% | |
| Iran | 192 | 12.7% | |
| China | 158 | 10.5% | |
| Democratic People's Republic of Korea | 73 | 4.8% | |
| Barbados | 72 | 4.8% | |
| Liberia | 58 | 3.9% | |
| Palau | 54 | 3.6% | |
| Venezuela | 38 | 2.5% | |
| Comoros | 37 | 2.5% | |
| Cook Islands | 36 | 2.4% | |
| Gabon | 31 | 2.1% |
Methodology
- Counted by vessel, not tonnage: OFAC records a usable tonnage figure for under ~4% of designated vessels, so a tonnage weighting would come from an unrepresentative sample.
- The flag-transparency tier is the SAME classifier the ArcNautical vessel dossier uses (jurisdiction-tiers): Tier 1 = public beneficial-ownership register (EU/UK/Norway/Iceland); Tier 3 = classic flag-of-convenience / tax-haven registry where UBO disclosure is restricted; sanctioned-state flags are reported separately from commercial flags of convenience.
- Excludes the 53 designated vessels with no recorded flag in the SDN feed.
Source: U.S. Treasury OFAC Specially Designated Nationals (SDN) list. Computed by the same ArcNautical engine behind arcnautical.com/check (commit 4df8f50df). Full scoring detail: methodology.
FAQ
What flag do most sanctioned vessels fly?
Of 1,506 OFAC-designated vessels with a recorded flag (data as of 2026-10-15), 47.2% fly a flag-of-convenience / shell-jurisdiction register where beneficial ownership is intentionally restricted. Only 0.4% fly a flag from a jurisdiction with a public beneficial-ownership register.
How is "flag of convenience" defined here?
A registry classified Tier 3 by ArcNautical's jurisdiction-tier model — a classic flag-of-convenience / tax-haven register (e.g. Panama, Marshall Islands, Liberia) where beneficial-ownership disclosure is deliberately restricted. It is the same definition the ArcNautical vessel dossier uses.