Insights · Data · Ageing tanker fleet
Tankers used to be scrapped at around twenty. Sanctions changed the maths: a generation of old hulls that should have gone to the breakers is instead carrying barrels the mainstream market won't touch — and the over-21 fleet has more than tripled.
For most of the modern oil trade, a tanker had a working life of about twenty years. Insurers, charterers and class societies treated that as the threshold beyond which a vessel was a liability, and ships were sold for recycling on roughly that schedule. Sanctions broke the schedule. An ageing tanker that could no longer find legitimate work suddenly had a buyer willing to pay a premium for exactly that — a hull with no Western ties to lose.
The result is a measurable greying of the tanker fleet, and the numbers are stark. Per UNCTAD and AXSMarine analysis, the sanctioned shadow fleet now averages around 21 years old and accounts for roughly 7.4% of the global tanker fleet — a small slice by count, but an outsized one by risk.
The clearest single statistic is the growth at the old end of the age curve:
| Year | Tankers over 21 years old |
|---|---|
| 2018 | under 400 |
| 2025 | over 1,440 |
That is more than a threefold increase in seven years. The curve does not bend like that for demographic reasons — a fleet does not naturally age that fast. It bends because recycling slowed at the same moment demand for old tonnage surged. Hulls that the market would have retired stayed in service, and new old hulls kept joining the over-21 cohort faster than any were leaving it for the beach.
A tanker fleet that should be retiring is instead getting older, because sanctions made an old hull an asset rather than a liability. UNCTAD and AXSMarine analysis
Age is not just a number on a certificate. Older tankers are more prone to structural fatigue, machinery failure and pollution incidents, and the shadow-fleet vessels carrying that age are frequently outside reputable classification and proper insurance. Put an under-maintained 22-year-old tanker, with thin or fictitious cover, into a busy strait and the downside is not abstract — it is a spill nobody is financially equipped to clean up. This is why the ageing fleet is treated as an environmental and navigational risk on top of the sanctions question.
It is also why age is one of the most useful first-pass signals when you are trying to identify a shadow-fleet vessel. As we set out in the shadow fleet, by flag, around 82% of the identified dark tankers are over 15 years old. Build year does not prove anything on its own, but combined with a recent reflag, an opaque owner and a patchy AIS trail, it sharpens the picture fast.
The flip side of a fleet that won't retire is a recycling market that has gone quiet for tankers even as it churns through other ship types. Where these vessels do finally end up — and the human and environmental cost of how they get there — is the subject of our piece on ship recycling. For now, the sanctions trades are deferring that day, which is precisely why the average age keeps climbing.
To assess an individual tanker you need its build year set against the rest of its file: flag, ownership, and sanctions standing. All of it hangs off the one identifier the ship cannot change — its IMO number. The Marifest registry records build year on every vessel file alongside the flag and a verdict from the compliance screen, so you can read a tanker's age as one signal among several rather than chasing it across a dozen sources. When an old hull reflags or renames to look fresh, the IMO number ties the new entry straight back to its actual age.
How Marifest uses it
Marifest puts a tanker's age next to its flag, ownership and sanctions verdict, so the ageing-fleet signal reads as part of a profile rather than a stray data point.
Build year is recorded against the permanent IMO number, so a rename can't disguise how old a hull really is.
The shadow-fleet pattern is a combination, not one number — Marifest surfaces all of it in a single vessel record.
Each old tanker is matched against OFAC, EU, UN and UK lists on its IMO number, the key a reflagged vessel cannot shed.
Look up any of 97,000+ vessels by name or IMO and read the age and the rest of the file at no cost.