Vessel identity by MMSI: current static data and observation log

Flag derived from the MMSI's Maritime Identification Digits (ITU MID table). It is the flag of the ship station licence: usually, but not always, the registry flag. null when the MMSI is not a ship station (coast stations, SAR aircraft, AIS-SART/MOB/EPIRB, aids to navigation, handhelds) or its MID is not allocated.

Estimated deadweight from AIS dimensions, not a registry value: tonnes = k x length x beam x draught, with k per hull (block coefficient, waterline length and lightship share folded into one factor) calibrated on vessels with published deadweight. null for implausible dimensions and for ship types where deadweight does not apply or the hull is unknown (tugs, pilot, search and rescue, port and law enforcement craft, military, sailing and pleasure craft, high speed craft, other and unknown types).

Official sanctions lists that name the current IMO number (empty when none or no IMO)