  Despite extensive research into ship detection via remote sensing, no studies
identify ship-to-ship transfers in satellite imagery. Given the importance of
transshipment in illicit shipping practices, this is a significant gap. In what
follows, I train a convolutional neural network to accurately detect 4
different types of cargo vessel and two different types of Ship-to-Ship
transfer in PlanetScope satellite imagery. I then elaborate a pipeline for the
automatic detection of suspected illicit ship-to-ship transfers by
cross-referencing satellite detections with vessel borne GPS data. Finally, I
apply this method to the Kerch Strait between Ukraine and Russia to identify
over 400 dark transshipment events since 2022.
