The action of 12 December 1782 was a naval engagement fought off the coast of Spain near Ferrol, in which the British 40-gun fifth rate HMS Mediator successfully attacked a convoy of five armed ships. Mediator succeeded in capturing one American privateer, the Alexander, and then captured the French ex-ship of the line La Ménagère. The convoy was part of Pierre Beaumarchais's supply chain to the American colonists.
What exactly was the action of 12 December 1782
The action of 12 December 1782 was a naval engagement fought off the coast of Spain near Ferrol, in which the British 40-gun fifth rate HMS Mediator successfully attacked a convoy of five armed ships. 

Mediator succeeded in capturing one American privateer, the Alexander, and then captured the French ex-ship of the line La Menagere. The convoy was part of Pierre Beaumarchais's supply chain to the American colonists.