 The Battle of Cape St. Vincent was a naval battle took place off the southern coast of Portugal on 16 January 1780 during the Anglo @-@ Spanish War . A British fleet under Admiral Sir George Rodney defeated a Spanish squadron under Don Juan de Lángara . The battle is sometimes referred to as the Moonlight Battle because it was unusual for naval battles in the Age of Sail to take place at night . It was also the first major naval victory for the British over their European enemies in the war and proved the value of copper @-@ sheathing the hulls of warships . 
