The Principle of Exclusive Flag State Jurisdiction

The principle that a ship is subject to the exclusive jurisdiction of the flag State on the high seas is firmly established. But given the prevalence of open registries and the multiple challenges in the maritime sphere, such as maritime safety, the popularity of cruise holidays, the promotion of human rights for those working at sea, and the need to combat iuu fishing, is it any longer tenable to slavishly follow the principle? International instruments and judicial decisions have emphasised the responsibilities of flag States. But States have also increasingly turned to other mechanisms, especially port State control, to deal with the various problems.