Observed positions
Click a vessel for its observationDashed boxes: experimental screening geofences
Coast: Natural Earth 1:50m / not for navigation
Tracker card
AIS-only / low confidenceVessel evidence
Dwell is a lower bound on continuously observed presence, not time awaiting berth| Vessel / MMSI | Screening area | SOG (kn) | Observed dwell | Last seen UTC | Proxy |
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What this measures
Presence means a distinct MMSI inside a screening box, seen within 30 minutes of the selected time. Waiting proxy means reported speed below 1 knot. Dwell starts at the first continuous observation and resets after a gap over 30 minutes. Entry / exit means an observed box crossing with no coverage gap, not an inbound / outbound port call. JNPT is a provisional harbour box that may include Mumbai-port traffic. Mundra uses the bounding envelope of published General Anchorage A. Cargo is unknown unless independently verified; AIS cargo/tanker codes cannot separate containers, coal and crude.
What it cannot establish
No verified port queue, cargo type, oil volume, berth availability, closure status or total traffic count. AIS can be missing, spoofed or switched off. Coverage denominator is unknown. Study boxes are analyst-defined, not official anchorage limits. Satellite validation is layer 2 and is not included. Sources: AIS Stream · Natural Earth.