Operation Storm: Japan's Top Secret Submarines and Its Plan to Change the Course of World War II by John Geoghegan Page B

safe waters. After that the
Segundo
began zigzagging. 23
    I T TOOK THE
Segundo
only eight hours to cross the Panama Canal. By the evening of July 5, she was moored at the sub base in Balboa. 24 The crew marveled at the Pacific’s 18-foot tidal spread, but they didn’t have long to relax. Fulp conducted sound tests the next day to check on their noise-reduction efforts. When it came time for torpedo attack simulations, he pushed his men even harder.
    Balboa wasn’t all work and no play, however. When he wasn’t busy spotting periscopes, Ensign Johnson spotted a five-foot-long stuffed iguana in the Balboa officers’ club. Deciding it would look perfect in the
Segundo
’s wardroom, Johnson smuggled the reptile on board, along with a case of Old Grand-dad. 25
    Fulp left Balboa for Pearl Harbor on July 9. Drills were a daily routine along the way as he strove to build a proficient crew. It was slightly before noon on Tuesday, July 25, when the
Segundo
finally arrived at the submarine base at Pearl Harbor. After minor repairs, she underwent three more weeks of training. Finally, Fulp received orders for his first war patrol as captain of the
Segundo
.
    In accordance with ComSubPac Opord 268–44, the
Segundo
was ordered under way as a member of “Wilkins’ Bears,” one of three wolf packs bound for patrol between Mindanao, the second-largest island in the Philippines, and the Palau Islands, 500 miles east. Admiral Halsey’s plan was straightforward: deploy ten subs in three wolf packs to sink any Japanese warships that interfered with the American invasion of Palau. 26
    It was time to see what Fulp’s crew had learned. They were finally going to war.

C HAPTER 16
DECLINE
    B Y THE TIME THE
S EGUNDO
LEFT PEARL H ARBOR ON HER FIRST war patrol, Japan’s Sixth Fleet was so decimated, it threatened to disintegrate as a cohesive fighting force. During the three-month period the
Segundo
crew underwent training, Allied antisub patrols sank 25 Japanese subs. 1 This was practically half of all remaining Japanese subs, which left only 26 fully operational boats in the entire force. Considering there had been more than twice as many subs at the start of war, the Sixth Fleet was rapidly declining. 2
    May 1944 was an especially horrendous month. While Captain Fulp was preparing the
Segundo
for shakedown trials, the USS
England
(DE-635), accompanied by the USS
George
(DE-697) and USS
Raby
(DE-698), used ULTRA intelligence and a new weapon called a Hedgehog to locate and sink six Japanese subs in a row. 3 The boats were stationed in a picket line 30 miles northwest of New Ireland when the destroyer escorts found them. 4 The
England
had already helped sink the
I-16
on May 21. The next day they located the
RO-106
and sunk her as well. Using the Hedgehog, which launched contact-exploding depth charges in a circular pattern, the three escorts worked their way down the Japanese sentry line. Later that same day they found and sank the
RO-104
, followed by the
RO-116
, the
RO-105
, and the
RO-108
. By this point, Japanese intelligence had picked up so many U.S. naval messages boasting of a clean sweep that they hurriedly signaled the last two boats to disperse. 5 Later U.S. naval forces concluded that the six-sub sinking was the most brilliant antisubmarine operation in history. 6 If lost crews could speak, they might have found
brilliant
an infelicitous word choice, but it certainly exemplified shortcomings in Sixth Fleet sub tactics.
    As far as Nambu was concerned, sentry lines turned subs into sitting ducks. He’d even protested against them during a January 1944 conference at Truk. The loss of six subs had proved him right, but at great cost.
    Unfortunately, the loss in May was nothing compared to the disaster that followed in June. The IJN was still preparing for the decisive naval battle, even though the location kept shifting closer to Japan. The situation worsened when the IJN High Command made a stupendous miscalculation by