On the evening of 15th October 1799, the 38-gun British frigate Naiad, Captain Pierrepont, was patrolling off the coast of Spain when she sighted two 34-gun enemy frigates, the Santa-Brigida and the Thetis. Regardless of the odds against him, Pierrepont gave chase and, before dawn the following morning, also sighted the British frigate Ethalion, Captain James Young, which also joined the pursuit. At 7.00am. on the 16th the two Spaniards parted company and Pierrepont directed Captain Young to go after the Thetis whilst he engaged her consort. Despite her adversary's head-start, Ethalion's sailing qualities soon became apparent and, by 11.30am., she had caught up with the Thetis and begun to engage her in a furious action. Despite negligible casualties on both sides, Thetis only withstood the battering for an hour before striking her colours and surrendering. Only upon capture however, did Captain Young realise quite what a prize he had secured; instead of the usual contraband of war, Young discovered that Thetis was, in fact, homeward-bound from Vera Cruz (Mexico) with a priceless cargo of specie worth 1,385,292 Spanish dollars. The booty, which equated to £311,690 sterling, made Young a very rich man and, after successive promotions, he died a Vice-Admiral in 1833.