San Fermín was launched in 1779 and became an armed merchant corvette for the Gipuzkoan Trading Company of Caracas.

A British fleet under Admiral Sir George Brydges Rodney intercepted the convoy at Cape Finisterre and captured it on 8 June.

Rodney sent to Britain the vessels of the convoy that were carrying commercial goods, with the captured 64-gun ship Guipuzcoano providing the escort.

[7] On the evening of the 3 April 1781 St Fermin sailed from Gibraltar to Menorca with dispatches, together with the tender to Brilliant,[8] and a settee.

On the way to Menorca, about 10 miles off Málaga, St Fermin was captured after a chase by two Spanish xebecs the next day.