 Admiral Rodney was escorting a fleet of supply ships to relieve the Spanish siege of Gibraltar with a fleet of about twenty ships of the line when he encountered Lángara 's squadron south of Cape St. Vincent . When Lángara saw the size of the British fleet , he attempted to make for the safety of Cádiz , but the copper @-@ sheathed British ships chased his fleet down . In a running battle that lasted from mid @-@ afternoon until after midnight , the British captured four Spanish ships , including Lángara 's flagship . Two other ships were also captured , but their final disposition is unclear ; some Spanish sources indicate they were retaken by their Spanish crews , while Rodney 's report indicates the ships were grounded and destroyed . 
