Organized security groups are operational on board some commercial vessels. These are professional units comprised of personnel whose only duties are to ensure that the overall physical safety of the vessel is maintained. Since maritime law does not take a position regarding such services, it can be concluded that the formation and maintenance of them is legal. Nevertheless, in order for potential actions taken by such groups to be acknowledged as legal, they must not exceed repelling direct attacks on the guarded vessel. It is not likely that attempts will be made in the nearest future to bring this issue under the detailed regulation of international law. The principles guiding the actions o f security groups are governed by the laws of the country of the ship’s flag. The role of the security officer has increased significantly within the hierarchy of the ship’s command. On the majority of large passenger vessels this is now a full-time position, and the person in charge of security is directly subordinate to the captain.