by John Prados
The Japanese subs owned these waters for weeks. With no way to differentiate individual enemies, Marines called the irritating undersea craft “Oscar.” The I-121 and I-122 reported shelling Guadalcanal numerous times, and both also communicated with the lookouts. Lieutenant Commander Norita Sadatoshi’s I-122 stayed in Ironbottom Sound until ordered away to support fleet operations. When reporter Richard Tregaskis crossed the sound in a launch bound for Tulagi, to gather accounts of the biggest firefight of the invasion, a sub chased the little flotilla of three motorboats. The next day, August 13, an I-boat surfaced in broad daylight to bombard. At night, subs fired star shells, interrupting Americans’ sleep. Lieutenant Jack Clark of the Navy boat unit recorded that Oscar used to surface around midnight and make high-speed runs up and down the sound, creating waves that pushed his boats farther up the beach, making them harder to refloat. Oscar typically shelled at 6:00 a.m. and 3:00 p.m., Clark recalls. Meanwhile, profiting from the subs’ dominance, several times Imperial Navy destroyers came to bombard Lunga Point too. Because Vandegrift had no coast artillery, the Marines were powerless against them. A captured Japanese 75mm was wrestled into position on the shore, and Marines used field artillery to fire seaward. On August 14 a gunner rejoiced that his 105mm howitzer of I Battery, 11th Marines, had hit a submarine. Japanese officers simply learned to surface outside gun range, and destroyers stayed there too.
During late August, by Tregaskis’s account, submarine shells fell on Guadalcanal about every other night. When SOPAC mounted its first resupply sortie, the fleet used fast destroyer-transports timed to arrive at night, minimizing the submarine threat. Lieutenant Commander Fujimori Yasuo’s I-121 filed a sighting report of Allied cruisers and destroyers approaching Guadalcanal on August 22, which led to the torpedoing of U.S. destroyer Blue by a Japanese warship. The next day Commander Morinaga’s RO-34 launched torpedoes at supply ship Fomalhaut and was credited with sinking her. The Marine gunners shot back. Both sides missed, and one of RO-34’s expended tin fish washed up on the beach, but the Fomalhaut hightailed it away, depriving Cactus once more. The I-121, I-122, and Morinaga’s boat all received battle honors for their work off Guadalcanal.
As the Japanese submarines harassed the Americans however they could, Tokyo began to realize this was no raid. Guadalcanal would be a campaign, not a battle. Command was reorganized at Rabaul. Vice Admiral Tsukahara Nizhizo of the Eleventh Air Fleet became the new supremo on August 8. He controlled all Imperial Navy ground, maritime, and aerial operations in the Solomons. Tsukahara summoned fresh air groups, including the 26th Air Flotilla as a reinforcement, not a replacement for Yamada’s unit. Admiral Mikawa led Eighth Fleet under Tsukahara’s overall command.
At Hashirajima, where the Yamato arrived a few days after the invasion, Combined Fleet staff huddled over their charts. Admiral Yamamoto issued some orders even before the Savo Island battle. His measures included the dispatch of Tsukahara, aerial units, a recall of the heavy cruiser force then in the Andaman Sea, preparations for a midget submarine attack on the Ironbottom Sound anchorage, planning for a fleet sortie, and the creation of a Guadalcanal Reinforcement Unit to specialize in pushing troops and supplies onto Cactus. To lead the latter, Yamamoto chose Rear Admiral Tanaka Raizo of the 2nd Destroyer Squadron, then conducting antisubmarine operations off Japan. Yamamoto summoned the Second and Third fleets. The Third Fleet was Nagumo Chuichi’s re-formed Kido Butai. On the afternoon of August 10, in Yamamoto’s cabin on Yamato, the staff briefed admirals Nagumo and Kondo Nobutake, of the Second Fleet, on the roles they would play. The fleet would cover arrival of reinforcements on Guadalcanal, while the Japanese Army plus SNLF troops overpowered the enemy. Briefly distracted by an American deception—Nimitz sent a light cruiser toward Japan to mimic a repeat of the Doolittle raid—Yamamoto never wavered.
Radio intelligence became the Allies’ only instrument to watch this first stage unfold. The Imperial Navy was aware of that. Having recently modified their fleet code, the Japanese changed their radio call signs just before Watchtower, and again at mid-August. Allied codebreakers found indications that the Japanese intended to shift presently to yet another version of JN-25. Yamamoto sent key messages from Kure in a seldom-used personal code that had not been penetrated. The fleet also made efforts at radio deception and utilized special single-use codes. Commander Wilfrid J. Holmes, of Station Hypo, notes that the Allies were now reading codes used by the port director at Truk, plus local ones employed in the Marshalls and Carolines, not JN-25. Despite that, traffic analysis permitted a clear picture.
On August 13 Allied intelligence reported dispatches indicating an imminent movement of Kido Butai from Empire waters south. Four days later the fleet implemented its call sign change, always a suggestion of impending operations. Intelligence was aware the cruisers returning from the Andamans were scheduled to join the Second Fleet, Yamamoto’s major surface unit, at Truk between the nineteenth and twenty-first. Traffic analysis showed elements of the Second Fleet en route to Rabaul as its main body refueled at Truk.
While the Imperial Navy resorted to radio deception, having other units assume the call signs of their carriers, by August 17 the CINCPAC war diary noted this prospect. Meanwhile movements of destroyers associated with the Third Fleet gave notice that Nagumo was under way. But confusion persisted. That day SOPAC issued an intelligence summary declaring the Japanese carriers, though in Empire waters, were definitely heading south, if they had not already set out. Pearl Harbor felt less certain of the carriers, but confident that a strong effort to recapture Guadalcanal was in the offing. CINCPAC believed a surface fleet might reach Cactus around August 20, but one including flattops could not attack before the twenty-fifth. Captain Layton mentioned potential carrier movements repeatedly, but still located the Nagumo force in Japan on August 20, though he allowed that its tactical exercises could cover a sortie. As late as the twenty-second Layton placed at least Carrier Division 2 at home, despite knowing some messages for its commander were being sent to Truk. Layton’s summary that day explicitly drew attention to the possibility that the Kido Butai might have departed, undetected, at any point after August 16. The summary for August 23 affirmatively located Nagumo at sea, bound for Truk. At SOPAC, Admiral Ghormley had no doubt. He signaled Fletcher in the evening on the twenty-second, “INDICATIONS POINT STRONGLY TO ENEMY ATTACK ON CACTUS AREA 23–26 AUGUST.” However, even Ghormley was uncertain about Nagumo’s fleet, noting in his dispatch, “PRESENCE OF CARRIERS POSSIBLE BUT NOT CONFIRMED.”
The Japanese obtained at least tactical surprise. Kondo’s force steamed out of Hashirajima at 5:00 p.m. on August 11. Nagumo should have gone too but begged for a few more days to train pilots, sailing on the evening of August 16. Yamamoto departed for Truk with the main body at noon on the seventeenth. Emperor Hirohito sent the fleet a declaration of confidence through the Navy General Staff. Meanwhile, at Guadalcanal on the eighteenth, Admiral Tanaka’s destroyers delivered nine hundred troops of Colonel Ikki’s Army regiment. Rather than awaiting arrival of the bulk of his troops and equipment, plus the lead echelon of the Kawaguchi brigade, Ikki led his men in a vain frontal assault across a river against entrenched Marines. The Japanese were wiped out. On this news Admiral Nagumo canceled a stop at Truk and made directly for the battle area northeast of the Solomons. Tanaka, with the rest of Ikki’s troops plus the 5th Yokosuka SNLF, pressed on. When search planes discovered a U.S. carrier at sea on August 20, the die was cast. A sighting the next day confirmed the presence of a task force—Fletcher’s command.
The American game changer would be the “Cactus Air Force.” Watchtower’s objective had been to obtain the almost-completed Guadalcanal airfield, and General Vandegrift had worked overtime to finish it. The 1st Marine Division lacked construction equipment—this had sailed away with Turner’s ships—but the Marines captured a bulldozer, five steamrollers, and the narrow-gauge mining railway. Vandegrift remembers that the two gasoline-powered mine cars were key. There was no other
way to move the more than 7,000 cubic yards of earth necessary to finish the runway. There were also cement mixers, thirty tons of high-grade concrete, fifty to sixty tons of steel plate, a few hoisters, and two generators. And the 1st Marine Engineer Battalion benefited from the Japanese work, including most of the runway, several bomber-size revetments, five open-sided hangar workshops, and aircraft dispersal areas cut out of the surrounding coconut palms. Marines declared the runway complete on August 12.
Several days later American destroyer-transports came to Lunga Point to deposit Lieutenant Colonel Charles L. Fike, executive officer of Marine Air Group (MAG) 23; a portion of his staff; sailors of CUB-1, a naval base unit, who substituted for mechanics; ammunition and parts; 400 barrels of aviation gas; and 300 bombs. Captured gasoline had impurities making it unsuitable for U.S. aircraft engines, but here were resources for combat. On August 20 Fike christened the base for Lofton Henderson, a Marine pilot lost defending Midway Island.
That day escort carrier Long Island launched the first planes for Henderson Field. They became the Cactus Air Force. This initial group comprised nineteen Wildcat fighters of Major John L. Smith’s VMF-223, plus twelve Dauntless dive-bombers of Marine Squadron VMSB-232. Another squadron of each was still in the pipeline. With the Long Island then the only U.S. escort carrier in the Pacific, the buildup would be slow. Army Air Force planes appeared on August 22 with Captain Dale Brannon, a flight of five P-400s of the 67th Fighter Squadron. The Cactus Air Force suddenly threatened every enemy ship and unit within its air range.
The new battle began with a convoy carrying the troops who were the focus of the KA Operation. This was Admiral Tanaka’s reinforcement unit. Tanaka, his destroyer squadron shorn of its divisions and reassembled with assorted warships, worried they would not cooperate well, but he had Admiral Mikawa’s firm decree to move the Ikki and SNLF troops. Tanaka’s fast destroyers had delivered Ikki’s advance guard in good order, though the Army wasted that success with its stupid attack. One destroyer that stayed at the landing point was damaged by a B-17, forcing her return to Truk in company with a second; then a third was hit by U.S. carrier aircraft, clinching suspicions of the presence of Fletcher’s task force. Tanaka turned his slow convoy around to mark time, ignoring conflicting orders from Mikawa and area commander Tsukahara. Then he learned U.S. aircraft had arrived at Henderson Field, strengthening his foreboding. Tanaka drew blood when destroyer Kawakaze, detached for a futile mission, torpedoed U.S. destroyer Blue. Meanwhile Mikawa radioed that the Japanese surface and carrier forces would be in place on August 23, giving Tanaka a position for that day, plus instructions to prepare the troop arrival for the twenty-fourth. But on the twenty-third, about two hundred miles from Cactus, Tanaka again received conflicting orders, with Mikawa directing him to head north, requiring a one-day postponement, while Tsukahara charged him to proceed as planned. Atmospheric disturbances played havoc with radio transmission, preventing Tanaka from resolving this dilemma.
A PBY Catalina found Tanaka’s convoy that morning, but lost it in squalls. Fletcher launched an afternoon strike anyway, with planes led by Saratoga air group boss Commander Harry D. Felt, another future CINCPAC. Major Richard C. Mangrum’s VMSB-232 dive-bombers took off from Cactus too. Along the storm front neither unit found the convoy. Both flew to Henderson, since Tanaka’s reported position put Commander Felt’s planes too far afield to return to the ship.
Under pressure to neutralize Henderson so troops could land, Yamamoto ordered Kido Butai to detach a carrier to rush ahead and smash it. He knew American flattops were present. There had been carrier air attacks and sightings, and submarine I-122 had reported attack by carrier aircraft off the Santa Cruz islands on August 20 (U.S. carrier aircraft claimed a record number of attacks on submarines during this period). But weather aborted strikes from Rabaul for two days running. In the predawn hours of August 24, Nagumo sent Hara Chuichi forward with light carrier Ryujo. Lookouts on Tanaka’s flagship Jintsu actually spotted the Ryujo with heavy cruiser Tone, wearing Admiral Hara’s flag, passing along the eastern horizon. That was before the main action, for daylight brought what has since been known as the Battle of the Eastern Solomons.
Both sides worked at a disadvantage. The Imperial Navy lost its surprise when U.S. air scouts spotted Vice Admiral Kondo’s Advance Force, as well as Hara’s detachment speeding to its attack position at twenty-six knots. So far the Japanese had no direct information. But Admiral Fletcher had his own disadvantages. The previous evening he had detached the Wasp’s unit to refuel (!), reducing Task Force 61 to Saratoga and Enterprise—and now part of Saratoga’s air group was at Henderson Field. These planes needed to return and rearm before Fletcher could strike. Their departure from Cactus was duly observed by Japanese troops at 9:30 a.m. Tanaka received that report and prepared for a mass assault, but really the Americans were merely regrouping aircraft.
The Ryujo launched her Cactus bombing, which led to a swirling dogfight over Guadalcanal so fierce that the JNAF barely touched Henderson. Aboard escort destroyer Amatsukaze, skipper Hara Tameichi watched the Ryujo with increasing apprehension. Her flight activity appeared sluggish, seeming to confirm Navy scuttlebutt that the best aviators were never assigned to these older carriers. Everyone knew Ryujo had been spotted. Commander Hara (no relation to the admiral) had just wolfed down lunch when a half-dozen B-17s appeared. They missed. Meanwhile Fletcher had launched Harry Felt’s air group against Ryujo at 1:45 p.m. On the Japanese side, fighters were preparing to launch when Felt’s Saratoga planes appeared from the southeast. Ryujo stood little chance. Quickly hit by four bombs and a torpedo, the carrier’s starboard engine room flooded. The vessel leaned to expose her waterline. Though fires were extinguished, she had no power. The inclination increased until Ryujo heeled over and sank. No Allied aircraft witnessed this, so the Americans launched a repeat strike, finding nothing. Only a month later, in late September, did U.S. intelligence report the Ryujo as sunk. They never knew for sure until intercepting an early 1943 notice striking the vessel from the Imperial Navy list.
With Saratoga’s strike in progress, Enterprise scouts discovered the Nagumo force an hour later. Some of “Big E’s” scout bombers dived on cruiser Maya. Two others, about to attack lesser warships, suddenly saw carriers in the distance. They shifted to Captain Arima Masafumi’s Shokaku. Lieutenant Ray Davis and Ensign Robert C. Shaw piloted the Dauntless aircraft that went after Arima at 3:15 p.m. The Shokaku, newly equipped with radar, actually detected the planes, but ignored the warning until lookouts also spotted them. At the last minute Captain Arima turned his vessel, and the American bombs were near misses, one barely a dozen yards away. It had been an awfully close call.
The Japanese made frantic efforts to locate Fletcher’s carriers. That morning two JNAF scouts got close to Task Force 61, but its radar-directed fighters blasted them before they could report. The Nagumo force dispatched a morning search of nineteen “Kates” and seven “Jakes” while readying an attack wave. Japan’s carrier admiral had learned some things from Midway. But the snoopers found nothing. A later floatplane from cruiser Chikuma finally discovered Task Force 61. It too was shot down—in the middle of transmitting, before sending the position. Sharp staff work by Nagumo’s air officer and navigation specialist estimated Fletcher’s location by computing where the scout must have been along its allotted course. The Kido Butai immediately began launching—this rapidity was another Midway lesson. Indeed, Shokaku was doing that when the Americans bombed her. She sent up eighteen Vals and nine Zeroes led by Commander Seki Mamoru. The Zuikaku contributed six more Zeroes and nine Vals. Nagumo hastened a second strike, led by Lieutenant Takahashi Sadamu, totaling twenty-seven Vals and nine Zeroes from both aircraft carriers.
Reports of Nagumo’s carriers reached Fletcher with Saratoga’s air group away for its attack on Ryujo, and half of Enterprise’s bombers still completing searches. The Saratoga managed to field a small group of seven bombers and torpedo planes, and another unit
of twelve TBF “Avenger” torpedo planes for the repeat attack on Ryujo. They never found Nagumo, but attacked Vice Admiral Kondo’s group instead, inflicting some damage on the seaplane tender Chitose.
At 3:36 p.m. Admiral Fletcher approved Admiral Thomas Kinkaid’s recommendation to catapult the available Enterprise planes. She put up thirteen Dauntlesses to attack Ryujo. But the carriers needed more Wildcats for combat air patrol. The task force was completing its fighter launch when Commander Seki’s strike wave appeared on Enterprise radar. Defense went to the fore. The aerial melee failed to prevent Japanese pilots from pressing home their attack. Shokaku planes concentrated on Enterprise, while Zuikaku’s bombers went after the Saratoga. Interceptors followed the JNAF planes right into the hail of the American AA fire. Lieutenant Elias B. Mott, an Enterprise gunnery officer, recalled, “We were completely unable to see the planes, due to the fact that they were so high and so small, and that it was late in the afternoon and the sky was considerably bluer than it would have been earlier.” At 4:44 p.m., one of the Japanese dive-bombers connected, putting a 550-pound bomb through the “Big E’s” number three elevator. Two minutes later another bomb holed her flight deck. More dive-bombers scored near misses, one so close it dented the side of the carrier. The planes headed for Saratoga—obscured in a squall—attacked battleship North Carolina instead. Only thirteen Japanese planes returned, but Enterprise was out of commission. She could not attack.
Lieutenant Takahashi’s second wave missed the Americans. Pursuit into the night by Admiral Kondo’s surface ships did not catch Fletcher. The Saratoga emerged untouched. On the Enterprise, skillful damage control restored ship handling. Refugees of “Big E’s” Air Group 10, foiled in attacking Ryujo because they could not find her, flew to Henderson, where they would fight alongside Marine air. The vessel herself would be hors de combat for weeks. North Carolina and a destroyer suffered minor damage. The Japanese incurred the loss of light carrier Ryujo, and damage to Shokaku, Chitose, and a few other vessels, but seventy planes were destroyed and precious aircrew killed. American aircraft losses were just twenty-three. Fletcher’s task force steamed south to refuel. In his roundup to Admiral King, Nimitz reported, “INTERCEPTS INDICATE TWO CARRIER GROUPS GENERALLY NORTHEAST OF MALAITA AND LAST NIGHT WITHIN 150 MILES OF THAT PLACE. RYUJO IN WESTERN GROUP DAMAGED AND REPORTED BURNING FIERCELY. SHOKAKU AND ZUIKAKU IN EASTERN GROUP…DURING THE NIGHT 7 DDs SHELLED CACTUS.”
