The only identifier connecting static and position AIS messages together through time is the vessel’s MMSI, a nine-digit number which is assigned to an AIS unit upon registration. Unfortunately, MMSIs are manually entered into the AIS unit by the technician, and may be incorrect.

As a result, multiple vessels may be transmitting with the same identifier. Since this identifier is no longer unique, their positions and static details would get jumbled together.

Starboard analyses every message as it comes in to determine if multiple positions from the same MMSI are indeed the same vessel. It looks at factors such as feasible travel speeds to determine if a new position was physically possible given the last reported position. If not, that position is assigned to a new unique Starboard vessel ID. Subsequent positions from two vessels sharing a MMSI are then untangled and assigned to the correct vessel ID.