Overview

A Dark Rendezvous event is triggered when a single vessel transmitting AIS displays rendezvous-like behavior for at least 15 minutes. 

This is not a guarantee that a vessel is rendezvousing with another vessel. Instead, it is an indication that it's movement (speed, course) is similar to that of a rendezvous. Analysts should analyze the tracks closely in consideration with any additional information available.

Machine Learning Model

This event is created using Machine Learning where the model examines the trajectory of the vessel to identify potential rendezvous behavior. A second vessel not transmitting AIS may be present and a rendezvous partner but is not visible to Skylight.

Ground truth data to create such a machine learning model is limited. Thus, Dark Rendezvous events also capture various other anomalous movements such as change in course and speed. These types of movements (and corresponding Dark Rendezvous events) are common for vessels awaiting approval for port entry, performing various maintenance checks, etc.

Events details

Standard information

Vessel information - name, MMSI, Type based on AIS data, IMO, Length based on AIS data

Date and time of the event

Location (lat/lon)

Event history - number of times Skylight has detected this behavior from this vessel

Additional information

Duration of the observed rendezvous-lie behavior.

Skylight also includes a list of vessels in the vicinity. These vessels were simply nearby the one vessel exhibiting the rendezvous-like behavior. It's possible that a vessel in that list may have rendezvoused with the vessel that generated the Dark Rendezvous event, but Skylight did not have enough information about that vessel's trajectory (e.g., AIS gap). 

Latency

Dark Rendezvous events can be generated in under one hour under ideal circumstances: clearly identify behavior with strong AIS signal.

Average latency is 4 hours.

Irregular/less frequent AIS signals will results in much longer delays (more than one hour).