Dark Fleet Tracker
AIS Gap MonitorOil tankers that disappeared from AIS at high-risk energy ports
23
vessels flagged
The dark fleet is a network of ~600 tankers that transport sanctioned Russian, Iranian, and Venezuelan crude by disabling or spoofing their AIS transponders. These vessels use ship-to-ship transfers, flag-of-convenience registries, and falsified cargo documentation to obscure oil origins. HarborSignal detects AIS transmission gaps at monitored energy ports — when a tanker present in one poll is absent in the next without a logged departure, it gets flagged.
How Detection Works
Track tankers
Every 6 hours we log all oil tankers and LNG carriers broadcasting AIS within monitored port zones.
Detect gaps
Vessels present in the previous poll but absent in the current one are flagged as AIS gaps — potential dark vessel events.
Score risk
Each disappearance is scored 0–10 based on port sanctions risk level, vessel behavior at last contact, and AIS identity quality.
Limitation: HarborSignal uses terrestrial AIS which only reaches coastal areas. Deep-water transfers are invisible without satellite AIS. Vessels may also disappear legitimately due to range or signal interference — risk scores account for context.
Monitored Energy Ports
Ras Tanura
Saudi Arabia's primary crude export terminal — Iranian/Russian tankers transship nearby
Singapore
World's largest bunkering port — major refuelling stop for dark fleet vessels
Houston
US Gulf Coast — monitors for sanctioned crude entering US supply chain
Sabine Pass
LNG export terminal — monitors for LNG cargo diversions to sanctioned buyers
Live Vessel Map — Persian Gulf
Live AIS tanker positions (ship types 80–89) via MarineTraffic · Persian Gulf / Strait of Hormuz
AIS Gap Events
LiveMMSI: 352744000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 525103010 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 574002350 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 563856000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 431778000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 563037800 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 352005046 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 563041900 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 412379040 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 574133000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 636022300 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 563182100 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 538003018 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 352004662 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 636021688 · Sabine Pass
sanctions risk
Watch on activity at Sabine Pass
MMSI: 566474000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 564886000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 249889000 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 352003617 · Singapore
sanctions risk
Watch on activity at Singapore
MMSI: 319017500 · Houston
sanctions risk
Watch on activity at Houston
MMSI: 352002925 · Sabine Pass
sanctions risk
Watch on activity at Sabine Pass
MMSI: 373263000 · Sabine Pass
sanctions risk
Watch on activity at Sabine Pass
MMSI: 368445000 · Sabine Pass
sanctions risk
Watch on activity at Sabine Pass
Trading the Dark Fleet
Why it matters for oil prices: The dark fleet transports an estimated 1.5–2M barrels per day of sanctioned crude — roughly 1.5% of global supply. A major crackdown (US secondary sanctions, port denials, insurance cancellations) would remove this supply from markets instantly, spiking Brent by $5–15/bbl.
Tanker stock angle: Dark fleet vessels primarily use old, uninsured tankers that compete directly with legitimate fleets. When sanctions enforcement tightens, dark fleet capacity shrinks — rates for compliant tankers (FRO, INSW, DHT) spike as the legitimate market absorbs displaced cargo.
Insurance and compliance: P&I clubs (marine insurers) are increasingly denying coverage to vessels that can't prove cargo provenance. A vessel losing insurance is often the first sign it's entering the dark fleet — and the trigger for legitimate tanker rate spikes.
AIS gap detection based on terrestrial AIS · Not all gaps indicate sanctions evasion · Legal