can you describe the history of it a few words?
It was previously called "Hairouna". This place was used for slaving expeditions by Columbus and the Spanish conquistadors.
Saint Vincent (Antilles)
Before 1498, the island was called "Hairouna" by its indigenous inhabitants. Columbus named the island Saint Vincent, since it is said to have been discovered on 22 January, the feast day of the patron saint of Lisbon and Valencia, Vincent of Saragossa.

Columbus and the Spanish conquistadors embarked on slaving expeditions in and around St. Vincent following royal sanction in 1511, driving the inhabitants to the rugged interior, but the Spanish were not able to settle the island. 
In the 1500s Columbus and the conquistadors noted there was a significantly large African population living amongst the native population, whom they assumed had come from shipwrecked slave ships or escaped from St. Lucia or Grenada to seek refuge in St. Vincent. They were called "Black Caribs," but are now known as "Garifuna".

The large population aggressively prevented European settlement on St. Vincent until the 18th century.
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. 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. which country used the flag that julien designed? Saint Vincent.
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Saint Vincent (Antilles) [SEP] History
Before 1498, the island was called "Hairouna" by its indigenous inhabitants. Columbus named the island Saint Vincent, since it is said to have been discovered on 22 January, the feast day of the patron saint of Lisbon and Valencia, Vincent of Saragossa. Columbus and the Spanish conquistadors embarked on slaving expeditions in and around St. Vincent following royal sanction in 1511, driving the inhabitants to the rugged interior, but the Spanish were not able to settle the island. In the 1500s Columbus and the conquistadors noted there was a significantly large African population living amongst the native population, whom they assumed had come from shipwrecked slave ships or escaped from St.