Inferred transshipments are possible transshipments where only the fish carrier vessel is visible on AIS. To detect inferred transshipments, Starboard analyses fish carrier movements looking for behaviours that match what we see during likely transshipments.
After analysing thousands of likely transshipments and discussing transshipments with fishing experts, we have developed the following rules:
The event must be between 4 and 48 hours long
The vessel is travelling at less than 3 knots during the event
The wind speed during an event must be less than 19.4 knots
90% of the event must occur during daylight hours
The wave height is less than 4 metres during the event
The event occurs more than 12 nm from shore
The vessel is travelling in a direction aligned with the wind
The vessel is consistently aligned with the wind direction for 90% of the event in one of three orientations:
Protecting the port side of the vessel from the wind
Protecting the starboard side of the vessel from the wind
Aligned in the same direction as the wind.
Likely and inferred transshipments in Starboard represent potential catch transfer between fishing vessels to fish carriers.
Both likely and inferred transshipments are shown as a dark red segment on the vessel track. The inferred transshipment icon includes a dotted arrow in the event icon.