Naval wars must have been messy affairs in the early days of sail and before standing navies. Privateers were a way of having a “pickup” navy with which to confront enemy shipping without having to support that ships & crews in peacetime. There wasn’t a whole lotta differentiation between merchant ships & warships then either.
True. The English relied heavily on privateers to augment their navy until the City of London became wealthy enough to build the fleet we think of today, which was nearly unbeatable.
I found the book on “the true story of Captain Kidd” -
It is called “The Pirate Hunter”, by Richard Zacks, 2002, ISBN: 0-7868-8451-7. He spent three years researching it.
It has a lot of pirate things in general that I thought were very interesting. (A “blood” reg flag was the original pirate flag. The skull and crossbones showed up fairly late, and the earliest record of the skull and crossbones was on some ship’s log indicating crew that had died.