These arrangements, which are common to any flag State, are supplemented by the control systems of a port State, which allow any State party to international conventions such as the International Convention for the Safety of Life at Sea (SOLAS), the Convention on the International Regulations for Preventing Collisions at Sea (COLREG), the International Convention on Load Lines, the International Convention for the Prevention of Pollution from Ships (MARPOL) and the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) to inspect ships flying a foreign flag that put into their ports in order to determine their seaworthiness and safety.
Ces mécanismes, communs à tous les États du pavillon, sont complétés par les systèmes de contrôle de l'État du port, selon lesquels tout État partie aux conventions internationales SOLAS, COLREG, LOAD LINE, MARPOL et STCW a le droit d'inspecter les navires battant pavillon étranger qui accostent dans ses ports pour en déterminer la navigabilité et la sécurité.