- Encounters may indicate potential transshipment activity between two vessels that both appear on AIS. Encounters are estimated using AIS data, including distance between the two vessels, vessel speeds, and duration in a given area.
- An encounter is defined as when two vessels, a carrier vessel and encountered fishing vessel, are detected on AIS data as within 500 meters for at least two hours and traveling at a median speed <2 knots, while at least 10 km from a coastal anchorage.
For both encounters and loitering events the duration can be filtered between 1 hour and greater than 48 hours based on user preference. This filter can enable a user to restrict possible transshipment events to those they consider more likely based on knowledge of duration of transshipment events.