CURVE OF TIME

Arrivals, time in port and the load/discharge inferred from the draught change, detected from AIS track history. An open call means the vessel is still in port (no departure observed yet).

1. Port of Prince Rupert

   no cargo change

   → · 21 h in port· draught 3.5→3.5 m
2. Port of Prince Rupert

   no cargo change

   → · 4 h in port· draught 3.5→3.5 m
3. Port of Prince Rupert

   no cargo change

   → · 2 h in port· draught 3.5→3.5 m

Method: each call is a run of fixes inside a port’s geofence confirmed by a stop (or an AIS gap); load/discharge is the sign of the draught delta over the call. Indicative: arrivals before our AIS history began read from the first observation.

Time-in-port summed by port from the AIS-detected port-call history: the ports this vessel has spent the most time at, longest first.

1. Port of Prince Rupert· Canada

   27 h
   3 calls · 9 h avg

Based on 3 completed calls observed since . Open calls (no departure yet) are excluded. The distribution sharpens as AIS history accrues.