[dragoon500ly]

On August 16th, the soldiers of the Ichiki Detachement's Second Echelon and the the 5th Yokosuka Special Naval Landing Force were on board three transports and escorted by a light cruiser and eight destroyers. What followed would turn into an intricate dance of alternating lunges toward and away from Guadalcanal. The convoy's movements were tied to the operations of the Combined Fleet.

The Japanese had assembled two large task forces comprising four battleships, four carriers, one escort carrier, sixteen cruisers, one seaplane carrier and thirty destroyers for operations around Guadalcanal.

Since the disaster at Midway, the IJN had been busy rebuilding its air groups and refining its tactical doctrine. The newly conceived doctrine would place the cruisers in a line some 150-200 miles in advance of the carriers, where they would be in position to finish off enemy ships crippled by carrier attacks as well as serve as a magnet for attacking American aircraft.

The carriers would operate in divisions of two fleet and one light carrier. The light carrier would be responsible for local protection and would operate an air group of twenty-seven fighters and nine torpedo bombers (for ASW protection). The fleet carriers would now operate an air group of twenty-seven fighters, twenty-seven dive bombers and eighteen torpedo bombers. The fleet carriers would be responsible for all offensive action. In order to supplement the air search capability of the fleet, the battleships and cruisers would carry the maximum number of floatplanes.

The fleet needed time to implement these changes and to conduct training, but the American offensive denied the IJN a respite. The staff of the 3rd Fleet (which had the carriers) were able to consult only briefly with the staff of the 2nd Fleet (battleships and cruisers) before the sailed. The only clear point to come out of the staff discussion was the need to defeat the American carriers took first priority; defending the reinforcement convoy was a distant second.

The USN's Task Force 61 (under Admiral Fletcher), with three carriers, one battleship, seven cruisers and eighteen destroyers, loitered in the waters to the southeast of the Solomon Islands, just out of range of the Japanese search planes based at Rabaul. Twice daily, Fletcher launched 200-mile air searches, but as at Coral Sea and Midway, he anticipated warning of the approach of the IJN from radio intelligence. But recent changes in the Japanese code prevented intelligence from reading the contents of messages and traffic analysis (RDFing and reading of call signs) would only be able to hint at Japanese intentions and maneuvers.

On August 16th, some intelligence officers interpreted the radio silence of 3rd Fleet to mean that it had sailed. But the Pacific Fleet summary for August 17th placed the IJNs fleet carriers in home waters, although it did acknowledge the possibility that they would soon set sail. At midnight on the 18th, the IJN threw a monkey wrench into the US radio intelligence efforts by changing all major calls signs, temporarily halting the most important source of insight from traffic analysis. Two days later, Pacific Fleet placed the IJN carriers in home waters and rated a sorte as a "slight possibility".

By August 21st, the Melbourne radio intel station suggested that the IJN carriers were at Turk, based on a single interepted message directed to the cruiser Chikuma (a known carrier escort). But doubts about the accuracy of Melbourne's call sign recoveries and the routing of dozens of messages for the carriers through Tokyo contradicated that surmise.

While the USN was baffled about the location of the Japanese carrier task force, the Japanese were equally perplexed about the location of the American carrier task force. On August 20th, flying boats spotted two American carriers 250 miles southeast of Guadalcanal. And on the 21st they interperted the last message of a Mavis reporting itself under fighter attack as confirming the location of the Americans. Orders went promptly to the reinforcement convoy to turn around in order to keep out of range of American aircraft. The Japanese 11th Air Fleet dispatched a strike of twenty-six Bettys and thirteen Zeros in a failed effort to attack the carriers; on their return trip, they decided to drop their bombs on Henderson Field. The Zero escort ran into a section of four Wildcats from VMF-223 at about 1207 hours. In the ensuing fight the Zeros claimed to have engaged thirteen Wildcats and shot down four , plus two probables. All of the American fighters were damaged, two would never fly again. The Americans claimed one Zero shot down (actually no Zeros were lost). Such was the reputation of the Zero at this time, that the mere survival of all four pilots caused squadron morale to zoom!