Select two ships on the map or choose an encounter.
Length (m)
Green: <50
Yellow: 50–<150
Orange: 150–<250
Red: 250–<350
Black: ≥350
Red warning: Projected encounter
Green warning: CRI 0 · zero score
Projected encounters, not confirmed collisions. CRI 0 does not confirm safety.
Select a ship on the map to see its details. Select a second ship to compare CPA and TCPA. Select a ship again to remove it from the pair.
Ships currently tracked in the monitored area. + shows ships added since the previous update; − shows ships removed from that update, not necessarily vessels that left the area.
Percentage of tracked ships with a reported name and all four vessel dimensions. This describes report completeness, not accuracy.
Average time since the tracked ships' latest AIS position reports were received. A lower age means fresher data.
Drag to project each ship's course and speed forward by 1–120 minutes. Longer vectors show more of the possible path. Selecting two ships sets the length to their time to closest approach; adjust it to explore other moments.
Distance between the two ships' latest reported positions. NM means nautical miles; 1 NM = 1,852 m.
TCPA (Time to CPA) estimates the minutes until the ships are closest together, assuming both keep their reported course and speed.
Pairs expected to pass within 0.5 nm in the next 10 minutes, based on reported movement. Only encounters with TCPA greater than 0 are listed, soonest first. CPA is their estimated closest passing distance; TCPA is the time until then. These are projected encounters, not confirmed collisions.
Select two ships to compare their movement. CPA (Closest Point of Approach) estimates how close they will pass if both keep their reported course and speed. TCPA is the time until that closest approach. Distances use NM (nautical miles) and metres; 1 NM = 1,852 m.
These encounters receive a score of 0 under the current model. A score of 0 does not confirm that an encounter is safe.
These encounters have a missing ship name or missing dimensions in the available AIS reports. They are shown separately because the information may not support a meaningful comparison.