who controls the port state?
It varies from place to place. For example the US Coast Guard handles port state control inspections in the US.
Flag of convenience
In 1978, a number of European countries agreed in The Hague to audit labour conditions on board vessels "vis-a-vis" the rules of the International Labour Organization. To this end, in 1982 the "Paris Memorandum of Understanding on Port State Control" (Paris MOU) was established, setting port state control standards for what is now twenty-six European countries and Canada.

Several other regional Memoranda of Understanding have been established based on the Paris model, including the "Memorandum of Understanding on Port State Control in the Asia-Pacific Region", typically referred to as the "Tokyo MOU", and organizations for the Black Sea, the Caribbean, the Indian Ocean, the Mediterranean, and Latin America. The Tokyo and Paris organizations generate, based on deficiencies and detentions, black-, white-, and grey-lists of flag states. The US Coast Guard, which handles port state control inspections in the US, maintains a similar target list for underperforming flag states
what is the flag of saint vincent and the grenadines? A Canadian pale triband. who designed it? Julien van der Wal . did it face any legal issues? Yes, as it is used as a flag of convenience by foreign merchant vessels. what was the reason for such adoption by these merchant vessels? It offers many advantages for them, such as less expensive fees and lax rules regarding crew, safety, and the environment. what were the working conditions? Low wages, long hours of forced work, minimum social standards, failing to pay the crew, abandoning the crew in distant ports, and low safety standards. did this business practice had to conceal their ownership? Yes, as it makes it hard to track the beneficial owner.
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Flag of convenience [SEP] Port state control
In 1978, a number of European countries agreed in The Hague to audit labour conditions on board vessels "vis-a-vis" the rules of the International Labour Organization. To this end, in 1982 the "Paris Memorandum of Understanding on Port State Control" (Paris MOU) was established, setting port state control standards for what is now twenty-six European countries and Canada. Several other regional Memoranda of Understanding have been established based on the Paris model, including the "Memorandum of Understanding on Port State Control in the Asia-Pacific Region", typically referred to as the "Tokyo MOU", and organizations for the Black Sea, the Caribbean, the Indian Ocean, the Mediterranean, and Latin America.