"one of those questionable cruisers, frequent in that day, which, without being absolutely outlaws of the deep, yet roamed over its surface with a remarkable irresponsibility of character"
An American privateer ship (1784)
Public DomainAn American privateer ship (1784) - Credit: Robert Dodd

These not-entirely-legitimate vessels are the boats of the privateers, whose disreputable trade bloomed in the sixteenth and early seventeenth centuries. Privateers were essentially pirates with whom the state colluded. The imperial governments of France, England, Spain, Portugal and the Netherlands lacked the money needed to defend their new colonies so would commission pirates to capture enemy ships and settlements, allowing them to keep a handsome portion of the booty in exchange for their services. Business was extremely profitable and many prominent traders, nobles and state officials devoted their assets to funding this arrangement. By the mid seventeenth century, though, it ceased to be tolerated as unsanctioned corruption mushroomed and more and more privateers refused to give any share of the plunder back to their employers.