This article examines the meaning and evolution of the practical implementation of the ‘genuine link’ concept over the years since the rise of the flag-of-convenience (FOC) registries in the 1920s. The author notes that while the competition between Flag States become fiercer, the regulations on ship safety, pollution prevention or shipboard working and living conditions are becoming standardized and ubiquitous. By being regulated by international instruments, in effect restricting regulatory powers of Flag States. Likewise, the enforcement of these provisions is becoming internationalized – with the omnipresence of classification societies and introduction of PSC regimes. At the same time, author identifies a lack of adequate regulations in respect of employment of seafarers, most notably wages and social security contributions, both at the national (Flag State) and international level. This legal loophole encourages Port States to introduce local solutions, irrespective of Flag State regulations. Such developments weaken the ‘genuineness’ of the ‘genuine link’ between ship and its Flag State.