The flag State jurisdiction is exercised on the basis of the nationality of a ship. Thus, the nationality of a ship is of central importance in order to establish the juridical link between a State and a ship flying its flag. Under international law, each State is entitled to determine conditions for the grant of its nationality to ships. In the M/V ‘Saiga’ case, ITLOS ruled:
Determination of the criteria and establishment of the procedures for granting and withdrawing nationality to ships are matters within the exclusive jurisdiction of the flag State.
However, the right of States to grant their nationality to ships is not without limitation. It is generally recognised that a State may not grant its nationality to a ship which has already been granted the nationality of another State. This requirement follows from customary international law and Article 92(1) of the LOSC which obliges ships to sail under the flag of one State only. The right of the State to grant its nationality to vessels may also be qualified by specific treaties, such as the UN Convention on Conditions for Registration of Ships (hereinafter the UN Registration Convention).
The validity of the nationality of a ship may be questioned in international adjudication. In the 2001 Grand Prince case between Belize and France, for example, ITLOS examined the question of whether Belize could be considered as the flag State of the Grand Prince when the application was made. The Tribunal then concluded that Belize failed to establish that it was the flag State of the Grand Prince. A related issue is whether the change of the ownership of a ship results in the change of the nationality of the ship. In this regard, ITLOS, in the 2007 Tomimaru case, took the view that ownership of a vessel and the nationality of a vessel are different issues and it cannot be assumed that a change in ownership automatically leads to the change or loss of its flag. This judgment provides an important precedent on this subject.
As noted, the juridical link between a State and a ship that is entitled to fly its flag is a prerequisite for securing effective exercise of the flag State jurisdiction. With a view to securing the juridical link, Article 5(1) of the Geneva Convention on the High Seas and Article 91(1) of the LOSC provide the requirement of a ‘genuine link’ between the flag State
and the ships flying its flag. Article 91(1) deserves quotation in full:
Every State shall fix the conditions for the grant of its nationality to ships, for the registration of ships in its territory, and for the right to fly its flag. Ships have the nationality of the State whose flag they are entitled to fly. There must exist a genuine link between the State and the ship.
In relation to this, Article 94(1) further requires that ‘[e]very State shall effectively exercise its jurisdiction and control in administrative, technical and social matters over ships flying its flag’.
According to ITLOS, ‘the need for a genuine link between a ship and its flag State is to secure more effective implementation of the duties of the flag State’. Yet the Convention on the High Seas and the LOSC leave entirely unspecified the concept of a genuine link. This situation creates at least two questions that need further consideration. The first is how it is possible to ensure a ‘genuine link’ between the flag State and the ships flying its flag in practice. It is particularly relevant to flags of convenience. The second question concerns the consequences to be attached to the absence of a genuine link.