NOTES TO TABLES 34 AND 35

The bulk of Naval air attack on shipping prior to 1944 is covered by the data for the Solomons-Bismarcks campaign, in Table 32A. Enemy shipping had also been attacked and driven from the Midway area and Eastern New Guinea in 1942, the Aleutians and the Gilberts in 1943. In 1944 the mobile carrier force, and Navy searchplanes operating from new bases won in campaigns spearheaded by the carriers, extended the area untenable for Japanese shipping to 10 additional sectors of the Pacific, including the Philippines, Formosa and the Ryukyus, and the Bonins. In 1945 Naval aviation extended the untenable area to include the entire Pacific and its connecting waters, with the sole exceptions of the Sea of Okhotsk, the Japan Sea, and the southernmost waters of the N.E.I..

Tables 34 and 35 show the progressive movement of naval air shipping attack across the Pacific. In most areas there is a standard progression: (1) a heavy carrier strike wiping out most of the major vessels in the area, followed by withdrawal of the remainder by the enemy; (2) the substitution of smaller vessels to run the loose blockade established by Naval search planes from new bases bordering the area, and a period of busy attack activity by these planes (3) a steady decrease in patrol plane attacks as all shipping disappears from the area. Variations from the pattern occur. In some cases the search planes preceded the carriers, or carrier strikes were not needed (Korea, China, Borneo); in some cases fighter bases were established the area and used to conduct an intensive campaign against coastal barges and small craft as well as ocean-going shipping, as in the Solomons, Marshalls, and Palau areas. But the eventual exhaustion of targets always came.

The Solomons-Bismarcks anti-shipping campaign ran out of ocean-going target vessels in March of 1944, and for the rest of that year was directed at barges. The New Guinea campaign was initially a Black Cat and subsequently a PB4Y enterprise, in which the carriers assisted while supporting the Hollandia and Morotai landings. In the Marshalls and Western Carolines the land-based attacks were all, after the month of the last carrier attacks, directed against barges and small boats useful for inter-island transportation of food and supplies for the enemy garrisons. The same was largely true of the land-based attacks in the Philippines. In the other areas most of these attacks were by patrol planes on ships of ocean-going types.

The geographical extent of these attacks, and their volume, can be seen from the tables. At one time or another Navy VPB were making at least 20 and up to 100 individual attacks on ships per month in each of the following areas:

New Guinea
Borneo, Celebes
Eastern Carolines
Bonins
Philippines
Ryukyus
Formosa
Japan
Korea, No. China
Central China
Indo China, Malaya

It can be seen that the effect of these many small, accurate attacks, spread throughout each area and throughout each month, while different from the crushing blows administered by carrier forces against concentrations of ships, could most effectively disrupt shipping movements and destroy a large number of vessels. Particular attention is invited to the VPB attacks on shipping in the waters of Japan, Korea and the entire Asiatic Coast from March 1945 to the end of the war. These attacks, largely by PB4Ys and PBMs, singly and in pairs, achieved an average volume of 400 per month during this period.

Of the carrier attacks particularly important are those in Formosa and the Philippines during September-November 1944, which completely broke up enemy reinforcement of the archipelago and accounted for a major part of the Jap Navy as well as substantial merchant tonnages (See Appendix). The progressive series of attacks through the Marshalls, Eastern and Western Carolines, Marianas and Bonins, from January to August 1944, while their combined volume was less than that of the Philippines anti-shipping campaign, were also important both in tonnage sunk and in size of ocean area cleared of the enemy.

In 1945 three carrier campaigns are outstanding: the January sweep of the entire South China Sea from Formosa to Indo China, the March strikes on Kyushu and the Ryukyus, and the heavy July offensive against the last Japanese shipping refuge - the Inland Sea - which crippled the remnants of the enemy's combat and merchant fleets.