The Eastern Fleet , commanded Control by Admiral Sir James Somerville , was forewarned Warning by intelligence and sailed Self_motion from its bases prior to the raid ; its attempt to attack Attack the Japanese was frustrated by poor tactical intelligence .

The main base of the Eastern Fleet relocated Departing to East Africa , and Ceylon was reinforced Cause_change_of_strength , but Admiral Sir James Somerville kept his fast carrier division , `` Force A '' , `` ... in Indian waters , to be ready GetReady to deal Resolve_problem with any attempt by the enemy to command Control those waters with light forces only . ''