A method, system (100) and product comprising: obtaining location-reporting signals of a vessel indicating that the vessel was located at a first geographical position prior to a shutdown event and at a second geographical position after the shutdown event; determining a distance between the first and second geographical positions; determining an estimated time to travel the distance based on the location-reporting signals; comparing the estimated time to the duration of the shutdown event, to determine whether the vessel had sufficient time to perform a dark activity that is associated with a maritime event; generating (220) a potential travel path from the first geographical position to the second geographical position, wherein the potential travel path comprises the maritime event; obtaining images that correspond to the duration of the shutdown event and to the potential travel path; and verifying (230) that the maritime event occurred based on an analysis of the images.