AIS Gap Detection

Detection mechanism

AIS gap: the platform opens a dark event once a vessel's position gap reaches or exceeds 6 hours — one global cutoff, applied the same way everywhere, not a coastal-vs-open-ocean split. Once a gap is open, a separate step that classifies its likely cause also checks a shorter 2-hour bar, gated on whether the platform has any active transfer hotspot on record at all rather than this gap's actual distance to one, and it only runs after the 6-hour cutoff has already been met — so it never changes which gaps get flagged.