 Agamemnon was part of Vice @-@ Admiral Robert Calder 's fleet cruising off Cape Finisterre on 22 July 1805 , when the combined Franco @-@ Spanish fleet from the West Indies was sighted to windward . The British ships formed into line of battle , with Agamemnon fifth in the line , and engaged Admiral Villeneuve 's fleet in hazy conditions with light winds . Agamemnon had three men wounded in the Battle of Cape Finisterre , and lost her mizzen topmast and the foresail yard . By nightfall , Calder 's fleet had become scattered , and he signalled for the action to be discontinued . 
