Maritime OSINT: Tracking Dark Ships & Shadow Fleets

**Executive summary:** This guide explains open-source methods and a toolkit for tracking vessels that disable or spoof AIS and for researching opaque ownership (‘shadow fleets’), covering core platforms (MarineTraffic, Equasis, TankerTrackers), satellite imagery, corporate and sanctions research, and an example investigative workflow to infer ship-to-ship transfers and sanctions-evasion indicators.