What ships do in the shadows:The rise of dark fleet

Global shipping is entering dark uncharted waters

While the dark fleet has long existed, its explosive growth is transforming global shipping risks at an unprecedented pace. In 2023, estimates suggested around 600 vessels were operating within this opaque segment of global shipping;

by 2026, that number is expected to rise to anywhere between
by 2026, that number is expected to rise to anywhere between
1,400 to 3,000+ ships.
1,400 to 3,000+ Ships

For insurers and brokers, this surge in obscured shipping practices means heightened exposure to compliance breaches, more complex claims and increased operational risk.

While dark fleet vessels themselves largely sit outside the conventional insurance market, their rapid expansion is reshaping the environment in which legitimate, insured shipping operates - influencing trade routes, loss severity and the complexity of claims across the wider marine market.

What is the dark fleet?

The term dark fleet is often used interchangeably with shadow fleet, but there are important distinctions.

  • Dark fleet Dark fleet
  • Grey Fleet Grey Fleet
  • Shadow Fleet Shadow Fleet
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Vessels that intentionally engage in deceptive practices to conceal their identity, movements or cargo in order to evade sanctions or regulatory scrutiny.

Common tactics include:

Disabling or spoofing Automatic Identification Systems (AIS)

Manipulating GNSS location data

Conducting ship-to-ship transfers in international waters

Repeated renaming, re-flagging and ownership changes

Dark fleet

Grey fleet is a newer, behaviour-based category that emerged after the Russia-Ukraine war.[1] It categorises vessels that display suspicious or anomalous behaviour such as irregular routing or registry changes, but are not formally sanctioned and may not deliberately disable tracking systems.

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Grey fleet

Grey fleet activity often sits just below enforcement thresholds, creating additional complexity for insurers and regulators.

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Shadow fleet

Vessels operating on the fringes of compliance, often supporting sanctioned trade through indirect or unclear means

A broader umbrella term that includes:

The dark fleet (intentionally deceptive vessels), and

Not all shadow fleet vessels are formally sanctioned, but their behaviour raises elevated risk indicators.

Explosive expansion

The rapid growth of the dark fleet has been driven less by shipping demand and more by geopolitics. Since the outbreak of the Russia-Ukraine war, successive rounds of sanctions on Russian, Iranian and Venezuelan energy exports have accelerated the use of older tonnage operating outside traditional market structures.

For underwriters and brokers, the growth of the dark fleet is less about individual vessels and more about second-order impacts such as:

  • ageing tonnage (vessels often 15-20+years old) operating alongside insured fleets,

  • increased likelihood of incidents occurring in politically sensitive or operationally constrained regions

  • rerouted trade through unfamiliar corridors

What to watch

As geopolitical tensions persist and sanctions regimes evolve, several developments are likely to affect both shadow activity and the wider, legitimate shipping market:

  • More sophisticated evasion techniques

    replacing simple AIS switch-offs, increasing background “noise” in vessel tracking data and making anomaly detection more challenging for all market participants.

  • Continued ageing of global tanker fleets

    particularly where newbuild supply remains constrained, elevating the risk of machinery failure, collision and pollution incidents across mainstream trade routes.

  • Rerouting of legitimate shipping

    to avoid high-risk regions, resulting in longer voyages, congested alternative corridors and increased exposure to weather, navigational and operational risks

  • More complex claims investigations

    with greater reliance on satellite imagery, AIS analytics and forensic voyage reconstruction, even for otherwise conventional losses.

  • Heightened regulatory and sanctions scrutiny

    extending beyond shipowners to charterers, ports, brokers and service providers, increasing compliance obligations and documentation requirements for insureds.

  • Operational strain at ports and terminals

    handling redirected energy flows, raising the likelihood of delays, contractual disputes and loss events linked to congestion and handling risk.

A complex future for shipping

Rising geopolitical tensions, sanctions and trade fragmentation are reshaping global shipping patterns and driving operational complexity across the legitimate maritime market. As trade is rerouted and risks become less predictable, incidents are more likely to involve disrupted documentation, heightened regulatory scrutiny and challenging loss environments.

Precision underwriting. Responsive partnership.

In an increasingly complex environment, experience and clarity matter. Starr's underwriters and claims specialists combine deep technical expertise with real-world judgement, working closely with brokers and clients to make confident, timely decisions when it counts. It's this blend of insight, data and empowered teams that brings clarity to complex maritime risks.

Our Marine team

Darren Stewart

Rebecca Hill

John O'Brien

Scott Heeley

Imogen Southcott

Johnny Shannon

Mark McDonach

Daisy Friend

Savraj Sohal

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