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 Ménagère " . The convoy was part of Pierre Beaumarchais ' s supply chain to the American colonists . Background . The Frenchman Pierre Beaumarchais founded a commercial enterprise , Roderigue Hortalez and Co . , supported by France and Spain . The French and Spanish supplied the American rebels with weapons , munitions , clothes , and provisions that would never be paid for . Beaumarchais contracted for the transport of the supplies in convoys . Even so , the Royal Navy captured many of the transport vessels . Baumarchais assembled one convoy in December 1782 . He met his captains in Bordeaux and then supervised the loading of his vessels . The plan was to sail for Port - au - Prince , Saint Domingue and then on to America to supply the American colonists . The convoy consisted of five ships . On 9 December 1782 the convoy sailed from the mouth of the Gironde for the West Indies and from there America . On 12 December , at 7 : 00am , HMS " Mediator " , under the command of James Luttrell , was sailing off Ferrol when she sighted the convoy . Action . At 8 : 00am the convoy formed in line of battle . Notwithstanding this formidable array , Captain Luttrell continued bearing down and at 10 : 00am " Ménagère " initiated the action . Luttrell saw that the shot came from the upper deck only and rightly concluded that the French vessel had no lower - deck guns . " Mediator " bore up in order to bring the rear ship to action . At 10 : 30 " Mediator " opened fire on " Dauphin Royal " when that ship and the " Alexander " bore up out of the line . " Aimable Eugénie " , " Ménagère " and the American brig then wore and endeavored to protect the two rear ships . " Mediator " fought her way through the Franco - American line . At 11a . m . Luttrell was able to cut off " Alexander " and compelled her to strike . He then took possession of the " Alexander " while the rest of the French and American vessels were trying to escape before the wind . Once Luttrell had succeeded in removing the prisoners and placing a prize - master and crew on board " Alexander " , he pursued the retreating ships . At 3 : 00pm the " Aimable Eugénie " hauled off the wind in full sail . " Mediator " then followed " Ménagère " . At 5p . m . he got within gunshot of " Ménagère " and started a running fight . At 9 : 00pm " Mediator " , having got up with the " Ménagère " , was on the point of firing a full broadside . Before she could do so " Ménagère " struck . At this point the action ended . Because the enemy fired high in an attempt to damage " Mediator " s rigging , she sustained no casualties . " Ménagere " had four men killed and seven or eight wounded . " Alexandre " had six killed and eight or nine wounded . " Dauphin Royal " and the American brig were seen next morning severely damaged but only five miles from Ferrol . However Luttrell judged it prudent to make sail for England with his two prizes . He had 340 prisoners on board and only 100 men to guard them while being close to Spain . Aftermath . " Mediator " sustained only seven casualties in her crew but was cut up in the riggings in masts which had been the target of the French and American ships . " Alexander " had six men killed and nine wounded ; " La Ménagère " had a passenger returning to Saint - Domingue and three seamen killed , and several men wounded . Despite being well - treated , Captain Gregory organized a party of the prisoners in an attempt to gain possession of " Mediator " . He was subdued but then unsuccessfully attempted to set fire to the ship . After this Luttrell had Gregory and the American prisoners placed in irons . Although the French officers played no part in the attempt , the British also guarded them more closely . Michael Seymour , who was later to be a rear admiral , served as a midshipman in HMS " Mediator " . " Aimable Eugénie " reached Saint - Domingue in March 1783 , where she wrecked on the coastal reef at Porto Plata . Luttrell and his crew received the last of the prize money for " Alexandre " and " Ménagere " in October 1788 . The action was the final clash of arms in which American forces were engaged before the Treaty of Paris concluded the American Revolutionary War .