Algorithm 2 Status Update Algorithm

1: For each set of bounding boxes with a given ID number that was present in the last 5 updates of the buffer (in the same round): 2:       Verify if the set contains at least 3 bounding boxes in the round; 3:       Verify if the average overlapping coefficient of the boxes’ areas for the set is greater than 0.2; 4:       Verify if the average change of angle between the bounding boxes in the set is less than 60 degrees; 5:       Verify if the centre of the bounding boxes is moving; 6:       If one or more of the above conditions are not met, discard the set in this round; 7:       Find the direction of movement of the vessel using the camera position information; 8:       Cut the vessels’ pictures from the original video stream using a set of bounding boxes (requires bounding box scaling to the original stream resolution); 9:       Create the output list with the pictures from the previous step—add the ID number and direction of movement to the output list; and 10:     Add the output list to the output list set. 11: If the vessel with the ID number has not been updated by the last 5 updates of the buffer, remove it from the buffer. 12: Return a set of output lists.