Cooke 's opportunistic diversion had determined that the Spanish forces in the Philippines posed no immediate threat , although the mission had cost 18 lives : Admiral Rainier later expressed his satisfaction with the outcome in a letter to the Admiralty . More might have been achieved with reinforcements : Historian C. Northcote Parkinson suggests that had Cooke 's squadron united with Resistance together they may have been able to destroy the disarmed Spanish warships at Cavite . He also notes however that in this scenario Pakenham would have been commanding officer , a man with considerably less imagination and guile than Cooke . Historian Richard Woodman was critical of the mission , considering the operation to have " no glorious outcome " and citing the failure to capture the treasure ships as its greatest short @-@ coming .