Even though most of the division’s heavy engineering equipment had disappeared with the Navy’s transports, the resourceful Marines soon completed the airfield’s runway with captured Japanese gear. On 12 August Admiral McCain’s aide piloted in a PBY-5 Catalina flying boat and bumped to a halt on what was now officially Henderson Field, named for a Marine pilot, Major Lofton R. Henderson, lost at Midway. The Navy officer pronounced the airfield fit for fighter use and took off with a load of wounded Marines, the first of 2,879 to be evacuated. Henderson Field was the centerpiece of Vandegrift’s strategy; he would hold it at all costs.
Although it was only 2,000 feet long and lacked a taxiway and adequate drainage, the tiny airstrip, often riddled with potholes and rendered unusable because of frequent, torrential downpours, was essential to the success of the landing force. With it operational, supplies could be flown in and wounded flown out. At least in the Marines’ minds, Navy ships ceased to be the only lifeline for the defenders.
While Vandegrift’s Marines dug in east and west of Henderson Field, Japanese headquarters in Rabaul planned what it considered an effective response to the American offensive. Misled by intelligence estimates that the Marines numbered perhaps 2,000 men, Japanese staff officers believed that a modest force quickly sent could overwhelm the invaders.
On 12 August, CinCPac determined that a sizable Japanese force was massing at Truk to steam to the Solomons and attempt to eject the Americans. Ominously, the group included the heavy carriers _Shokaku_ and _Zuikaku_ and the light carrier _Ryujo_. Despite the painful losses at Savo Island, the only significant increases to American naval forces in the Solomons was the assignment of a new battleship, the _South Dakota_ (BB 57).
[Illustration: _Of his watercolor painting “Instructions to a Patrol,” Capt Donald L. Dickson said that three men have volunteered to locate a Japanese bivouac. The one in the center is a clean-cut corporal with the bearing of a high-school athlete. The man on the right is “rough and ready.” To the one at left, it’s just another job; he may do it heroically, but it’s just another job._