NOTES TO TABLE 32A.

The predominance of land-based operations in the Solomons-Bismarcks area may be especially noted. Carrier offensive activity against land targets was largely limited to putting the Marines ashore in August 1942, and neutralizing Buka and Bonis airfields in support of the Bougainvillea landings in November 1943. The carriers concentrated solely on enemy shipping in the Coral Sea, Eastern Solomons, Santa Cruz and Guadalcanal battles of 1942, and in the Rabaul and Kavieng strikes of 1943-44.

Land-based aircraft were forced to devote a major part of their offensive effort to shipping targets during the first ten critical months of the Solomons campaign, to prevent enemy reinforcement of their forces and naval bombardment of our installations. A substantial antishipping effort continued throughout the balance of 1943 and 1944, reaching a peak in the early 1944 strikes which made Rabaul Harbor untenable, but after May 1943 land targets received far greater attention.

Peaks of offensive activity against land targets may be noted in July 1943 (direct support of New Georgia landings), November-December 1943 (Bougainville landings), March 1944 (Japanese counter-offensive on Bougainville). The decline in volume in January-February 1944 reflects the longer missions flown against Rabaul during these months, contrasted with the previous short-range hops in the Solomons. The heavy volume of attacks in July-November 1944 reflects the withdrawal of Army planes, leaving the principal responsibility of neutralizing the Solomons to an increased force of Marine aircraft operating from Bougainville, Green Island and Emirau. It also reflects the withdrawal of enemy air strength, permitting use of Marine VF entirely for offensive purposes.

In December 1944 the bulk of the single-engine planes were withdrawn from this area for transfer to the Philippines, leaving PBJs as the principal Naval aircraft remaining. This accounts for the larger bomb tonnage per sortie thereafter, and the cessation of shipping attacks, which during late 1944 had been largely fighter attacks on barges.

NOTES TO TABLE 32B

There were three main stages to the Naval air campaign in the Philippines: (a) the destruction of enemy air strength and shipping throughout the area (plus a minor amount of preinvasion shore bombardment and direct support) carried out by carrier forces during September October and November, 1944; (b) protection of the amphibious forces and direct support of ground forces by both carrier and land-based planes in the Mindoro and Lingayen landings of December and January; and (c) extensive ground support and pre-invasion bombardment by Marine aircraft in the Luzon campaign and subsequent invasions of the Visayas and Mindanao.

The table shows the considerable emphasis on shipping attack in the first stage; half of the bombing offensive was against enemy naval and merchant vessels, while the remainder of the bombing effort, plus most of the fighter offensive, was sent largely against airfields. The attacks of September-November 1944 in the Philippines constituted the Navy’s heaviest sustained anti-shipping offensive; they resulted (see Appendix) in 279,000 tons of combat vessels and 474,000 tons of large merchant vessels sunk (including attacks at Formosa and the Ryukyus). At the same time the air offensive resulted (see Table 26B) in the destruction of 1406 enemy aircraft in air combat and 1,295 on the ground.

By the beginning of the second stage, enemy shipping had been almost completely eliminated, and the enemy air force largely nullified. 676 more planes were destroyed, however, and substantial attacks were made on ground targets in support of ground forces.

For the third stage the carriers were no longer required, enemy aircraft were almost completely absent, and the bulk of the offensive consisted of direct air support of Army ground troops. The table shows the considerable volume of attacks flown by Marine fighters and dive bombers in the Philippines from December 1944 to the end of the war. Although the Marine offensive in this theater during these few months amounted to nearly a quarter of Marine aviation's total for the war, it has been practically entirely unpublicized.

NOTES TO TABLE 32C

The pattern of the Philippines campaign was repeated in the Ryukyus, but in more condensed form. Enemy shipping was more quickly and easily eliminated in March and April 1945 (it had already been hit in a one-day strike incidental to the Leyte campaign), but the airfields, which had been hit comparatively lightly in October and January, presented more difficulty. Those on Okinawa were quickly neutralized, but it was necessary to attack those in the Southern Ryukyus constantly through the entire 5 months of the operation. The bulk of the remaining offensive effort was concentrated on beach and inland defenses, and on guns, caves, and other defensive positions, in direct support of Marine and Army troops. In this work land-based Marine aircraft began to assist the carrier forces early in April; they assumed an increasing proportion in May and June, and on 22 June took over from the carriers the entire burden of support.

NOTES TO TABLE 32D

This table (see next page) shows the distribution of Naval attack effort between land and shipping targets in the various segments of Japan. (See Definitions for geographical limits of the various areas; note especially that the Tokyo area includes all of northern Honshu except the tip*.

Tokyo area land targets, particularly airfields, received the heaviest fraction of the carrier offensive, over 40% of the total attacks on land targets. These attacks were delivered in three periods; (a) the first strikes of 16, 17 and 25 February, were concentrated on airfields and aircraft factories, and resulted in the destruction of 203 grounded aircraft as well as 413 in air combat; (b) the strikes of 10-18 and 30 July, and (c) the final operations of 9-15 August. In the latter two periods 762 grounded enemy aircraft were destroyed in this area alone. Over half the enemy aircraft destroyed by the Navy in or over Japan, were in the Tokyo area. (See Table 26D).

In the Kyushu-Kure area, the next most heavily attacked, the offensive effort was spread over five months, though the heaviest concentrations were in March and May, in strikes aimed at breaking up enemy air concentrations capable of being employed against Okinawa. The April offensive involved also the strikes against the YAMATO and her escorts, which resulted in destroying the bulk of that suicide naval force.

Central Honshu, including the Kobe-Osaka (Inland Sea) area, and the Nagoya area, was attacked heavily only during the short period of 24-30 July. Half of the bombing effort was directed against shipping.

Hokkaido, and the adjacent tip of Honshu, were attacked only on 14-15 July and 9-10 August.

The heaviest carrier attacks on shipping in Jap home waters were on 21-28 July in the Inland Sea; in this series of strikes the bulk of the remaining Jap Navy was crippled.

Land-based Naval air attacks on Japan were carried out largely by Naval search planes, though Marine fighters from Okinawa were active against Kyushu from June on. Search plane targets were normally shipping, usually of the smaller types, along the coasts. It should be noted that the bomb tonnages expended in these attacks by single search planes are understated in the above table. Where such a plane dropped less than half a ton in an attack, it was recorded in the machine system as zero. Frequently 2 or 3 small bombs, and heavy strafing, were sufficient to destroy the small vessels encountered, and the remaining bombs of the usual load of a ton or less were saved for other targets that might be found.