Dimitri’s Reviews > Scratch One Flattop: The First Carrier Air Campaign and the Battle of the Coral Sea > Status Update

Japanese air defence against dive bombers relied primarily on the manoeuvrability of the carrier and its own AA. Like the USN, the escorting cruisers believed that torpedoes presented the bigger threats; the instinct was to disperse formation & concentrate on low-angle targets such as torpedo bombers.

Having approached to within 60/70 nautical miles of eachother the night of 6-7 May, the two carrier forces had been steaming away from eachother on nearly perpendicular courses since then; WNW vs due north... within the eye of the band of storms, whose edges reduced scouting planes' visibility.

Nimitz had just 4 carriers to combat what was believed to be more than twice that number of flattops. In reality, the Japanese had only 6 full size fleet carriers, 3 light carriers & an escort carrier (the controversial Shoho) which deployed fewer aircraft per flight deck & handled them less efficiently than the US. This went part way towards evening the balance ... but this closer examination contains hindsight.

But... 20th century fleets had less interchangeable components, while radio and airplanes took away the element of surprise.

By Postponing the new codebook until late May, IJN gave US codebreaking a crucial window for the duration of the Coral Sea campaign.

Port Moresby, New Guinea, was clearly next somewhere in April as "operation MO".

The roots of the Japanese penchant for complex plans with split forces can be found in samurai battles, fought on land between horsemen with swords. A strategy based on sending out small groups with instructions to reassemble at a distant point in time & space had power to enhance the chances of succes, while the loss of one or even several of these small & interchangeable groups would be unlikely to doom the plan.

AGREE CURRENT PRACTICE OF USING A SINGLE CARRIER IN AN IMPORTANT OFFENSIVE TASK WITHOUT SUITABLE COVERAGE BY SHORE BASED AIRCRAFT SHOULD BE AVOIDED

Here we see the difference with IJN practice of deploying battle groups centered on two carriers ...

"The logistic difficulties were the obones caused by the loss of the East Indies oil fields, meaning that every drop burned by ships in the South Pacific would have to be carried from the US west coast, far closer than the next close source, the British controlled fields in Iraq, still more than 5000 nautical miles (9200 km) away"