Indian Ocean raid

Indian Ocean raid
Part of the Pacific Theatre of World War II
British heavy cruisers HMS Dorsetshire and Cornwall under Japanese air attack and heavily damaged on 5 April 1942.
Date 31 March – 10 April 1942 Location Indian Ocean and British Ceylon Result Japanese victory
Belligerents
United Kingdom  British Ceylon  Australia Netherlands  United States  Canada	Japan
Commanders and leaders
James Somerville	Chūichi Nagumo[1] Mitsuo Fuchida
Units involved
Eastern Fleet	Combined Fleet
Strength
2 carriers 1 light carrier 5 battleships 7 cruisers 15 destroyers 7 submarines 100+ aircraft 30 smaller warships 50+ merchant ships.	5 carriers 1 light carrier 4 battleships 11 cruisers 23 destroyers 5 submarines 275 aircraft
Casualties and losses
1 light carrier sunk 2 heavy cruisers sunk 2 destroyers sunk 1 Armed Merchant Cruiser (AMC) sunk 1 corvette sunk 1 sloop sunk 20 merchant ships sunk 54 aircraft destroyed 825 killed	18 aircraft destroyed 31 aircraft damaged 32 killed

The Indian Ocean raid, also known as Operation C^[2] or Battle of Ceylon in Japanese, was a naval sortie carried out by the Imperial Japanese Navy (IJN) from 31 March to 10 April 1942. Japanese aircraft carriers under Admiral Chūichi Nagumo struck Allied shipping and naval bases around British Ceylon, but failed to locate and destroy the bulk of the British Eastern Fleet. The Eastern Fleet, commanded by Admiral Sir James Somerville, was forewarned by intelligence and sailed from its bases prior to the raid; its attempt to attack the Japanese was frustrated by poor tactical intelligence.

Following the attack the British expected a major Japanese offensive in the Indian Ocean. The main base of the Eastern Fleet relocated to East Africa, and Ceylon was reinforced, but Somerville kept his fast carrier division, Force A, "...in Indian waters, to be ready to deal with any attempt by the enemy to command those waters with light forces only."^[3] However, the Japanese had no short-term plans to follow up on their success, and within the year operations in the Pacific made it impossible to do so.