I may be wrong but this vessel may well be undergoing some kind of repairs to the hull on it's port side.. It may have been ballasted (probably with water) so that it leans to the starboard side. Work can be done on the port side below the normal water line. Note that there are securing ropes or chain running from the ship to structures in the water. This is probably cheaper than paying for a dry dock, particularly if it is a minor problem.