4.1.2 — Maritime Intelligence — maturity: live

Dark Vessel Tracking

Detecting and tracking vessels that are deliberately not transmitting AIS, by combining satellite radar, RF survey and optical imagery.

A dark vessel is one that is deliberately invisible to the public maritime tracking system. Some have switched off their AIS, some are spoofing a false location, and many — particularly smaller fishing vessels — were never equipped with AIS at all. Dark vessels are the operationally interesting ones: illegal, unreported and unregulated (IUU) fishing fleets account for an estimated 20–30% of global catch; sanctions evaders run "ghost fleets" of older tankers carrying Russian and Iranian crude; smugglers and human traffickers move along coastal routes that would make no operational sense for a transmitting vessel.

The detection stack relies on non-cooperative sensing. SAR is the foundation — Global Fishing Watch's operational pipeline processes around 400 SAR scenes per day and extracts roughly 20,000 daily vessel detections, of which a large fraction match no AIS track. RF survey from constellations like HawkEye 360 or Unseenlabs detects the radar, satphone and other emissions a vessel cannot easily switch off without being unable to operate. VIIRS night-light data catches squid jiggers and lit fishing fleets that don't transmit. The fused output is a dark-fleet density map. For India's western Indian Ocean concerns, GCC monitoring of Iranian sanctions evasion, and African coastal nations facing Chinese DWF (distant-water fishing) fleets, this is the single most operationally consequential satellite capability available today.

What matters

AIS-off and AIS-spoofing vessels make up a large share of every contested ocean — IUU fishing alone is estimated at 20–30% of global catch.
SAR and RF survey are the two sensors that work non-cooperatively; everything else is a confirmation layer.
India was approved in May 2025 for a USD 131M Foreign Military Sale of HawkEye 360 RF data — an explicit recognition that this capability is sovereign-relevant.
For African coastal states, dark-fleet monitoring is the difference between exporting fish and watching foreign vessels strip the EEZ.
The detection sensors are commercial; sovereign control over tasking is the strategic variable.

Sovereignty score: 9/10 — Critical, bordering on existential for coastal-state EEZ control.

Dark-vessel tasking touches sanctions enforcement, naval ISR and counter-smuggling — all areas where a foreign supplier's tasking priorities will sometimes diverge sharply from the host country's.
The US FMS process for HawkEye 360 to India shows the alternative — gated capability that requires a friendly relationship to remain.
For nations where the supplier is or could become an adversary (China for many Indian Ocean nations), foreign-only capability is unacceptable.

Reference architecture

Payload: X-band SAR (primary, all-weather). RF survey payload (passive multi-frequency receiver). Optical imager for confirmation. VIIRS-equivalent low-light optical for night detection.
Bus class: SAR: 100 kg ESPA-class. RF: 16U cluster-formation nanosats (HawkEye 360-style — three-sat clusters for time-difference-of-arrival geolocation). Optical: 6U–12U.
Orbit: 500–600 km SSO LEO for all sensors. SAR: 12–24 sats for daily revisit. RF: 7 clusters of 3 sats (21 total) for ~hourly revisit. Optical: 12+ sats for daily.
Ground segment: Sovereign ground stations within national territory are essential for tasking secrecy on this application. GSaaS acceptable for non-sensitive parts of the pipeline.
Software & data
Latency
Cost band
Lead time

References

Global Fishing Watch — Dark Vessels research — the operational state of the art on SAR-based dark fleet detection.
HawkEye 360 — overview and India FMS approval — documents the May 2025 USD 131M US Foreign Military Sale to India for maritime domain awareness over the Indo-Pacific.
Global Fishing Watch — Satellite Radar Imagery Helps Reveal the True Scale of Hidden Fishing — case studies including the North Korea and Natuna Sea dark-fleet investigations.
Global Fishing Watch — Detecting Dark Fishing in the North Natuna Sea — operational example of how a single AIS-transmitting vessel was found to be travelling with 15 dark vessels nearby.