The Caribbean of the late 17th and early 18th century was an ideal place for pirates. The small uninhabited islands and the wilderness on the larger ones provided them with countless hideouts.
Additionally, the fact that four nations were fighting for supremacy in the area made it easy for them to find allies and pose as privateers for one or the other faction.
The British were the most rapidly expanding power in the Caribbean at the time. The Spanish had already been there for more than 200 years and concentrated on South and Middle America. The French were
quite busy with their European wars most of the time and the Dutch made much higher profits in South-east Asia and India.