The Strategic Context of Summer 1945

By July 1945, the United States Navy’s submarine force had become the noose tightening around Imperial Japan’s neck. With the fall of Okinawa in June and B-29 firebombing campaigns reducing Japanese cities to ashes, American military planners were preparing for the inevitable invasion of the Japanese home islands. The U.S. Third Fleet, under Admiral William “Bull” Halsey, planned devastating naval bombardments along Japan’s coastline to soften defenses for Operation Olympic – the planned November invasion of Kyushu.

In this critical phase, American submarines played multifaceted roles that went far beyond their traditional commerce raiding missions. They became mine detectors, lifeguards for downed aviators, clandestine operatives supporting special missions, and naval gunfire spotters. The submarine force had transformed from a strategic afterthought in 1941 to an indispensable component of American naval power by war’s end.

Preparing the Undersea Assault

The Third Fleet’s planned July bombardments required unprecedented coordination between surface and submarine forces. Admiral Halsey’s staff requested submarines equipped with advanced FM sonar to sweep ahead of battleships and cruisers, detecting Japanese minefields that could cripple the bombardment force. This represented a significant evolution in submarine warfare doctrine – no longer just lone hunters, American submarines were now integrated into complex combined arms operations.

Two submarines stood out for this dangerous work: the USS Redfin at Guam and USS Gar at Pearl Harbor, the latter rushing to install the crucial FM sonar equipment. The plan called for targeting industrial sites along Honshu’s northeast coast, particularly the steel mills at Muroran in Hokkaido. These operations demonstrated how American naval strategy had progressed from early-war defensive measures to direct attacks on Japan’s industrial heartland.

The Lifeguard Submarines: Rescues Amidst the Storm

One of the submarine force’s most celebrated – and dangerous – roles was rescuing downed aviators. The dedicated “Lifeguard League” submarines stationed near bombing targets saved hundreds of airmen, often under fire from both Japanese defenses and tragically, friendly forces. The harrowing experiences of submarines like USS Toro and USS Balao highlighted the chaos of these operations:

– USS Toro narrowly avoided destruction when the destroyer USS Colahan opened fire at 7,400 yards, the submarine surviving only through emergency diving
– USS Balao endured repeated attacks from American aircraft despite clear identification procedures
– These “friendly fire” incidents underscored the challenges of coordination in the war’s final, frenetic months

The courage of these submarine crews was exemplified by USS Aspro’s dramatic rescue of an Army Air Force pilot in Sagami Bay, just eight miles from Kamakura’s Great Buddha. Under continuous attack by Japanese Zero fighters and bombers, Aspro’s crew persisted through multiple dive attempts before successfully retrieving the downed aviator.

Special Operations and Unconventional Warfare

American submarines demonstrated remarkable versatility in the war’s final months, undertaking missions that blurred traditional naval warfare boundaries:

– USS Barb’s legendary “train busting” operation along the Karafuto coast, where crew members went ashore to plant explosives on a coastal railway
– Planned raids on Japanese seal hunting stations for…questionable personal souvenir purposes
– Rocket attacks launched from submarine decks against shore targets
– Coordination with British XE-class midget submarines for attacks on Japanese heavy cruisers in Singapore

These operations showcased the submarine force’s adaptability and the creativity of its officers and crews. The Barb’s railway sabotage became particularly famous, though Japanese newspapers mistakenly credited the damage to aerial bombing – much to the crew’s amusement.

Technological Edge: The Tools of Victory

American submarine superiority by 1945 rested on several technological advantages:

– Advanced FM sonar systems for mine detection with ranges up to 1,700 yards
– Improved torpedoes with magnetic exploders, though crews remained (understandably) skeptical after early-war failures
– Effective radar systems allowing night surface attacks
– The reliable fleet submarines themselves, combining range, durability, and firepower

This technological edge, combined with Japan’s deteriorating antisubmarine capabilities, allowed American submarines to operate with near impunity in Japanese home waters by mid-1945.

The Human Element: Stories from the Silent Service

Behind the statistics and operational details were remarkable human stories:

– Commander John Corbus, veteran of three submarine commands, receiving the Presidential Unit Citation
– The bittersweet homecoming of the “Hellcats” wolfpack, greeted by cheering crowds and brass bands
– The dark humor of submariners volunteering for dangerous missions in exchange for $200 bonuses
– The tragic case of USS Bullhead, likely the last American submarine lost in the war, to Japanese aircraft on August 6

These personal narratives reveal the unique culture of the submarine service – highly skilled, tightly knit, and bearing the psychological burden of knowing each patrol might be their last.

The Final Tally: Assessing the Submarine War’s Impact

When Emperor Hirohito’s surrender announcement came on August 15, the U.S. submarine force could reflect on an extraordinary contribution to victory:

– 1,178 merchant ships sunk (5,053,491 tons)
– 214 naval vessels destroyed
– An estimated 70,000 Japanese merchant sailors killed or wounded
– Critical strangulation of Japan’s oil and raw material imports
– Only 52 U.S. submarines lost (18% of those that saw combat)

Perhaps most remarkably, this devastation was achieved by a force that never comprised more than 1.6% of U.S. Navy personnel. The submarine campaign against Japan stands as one of history’s most effective commerce raiding campaigns and a decisive factor in Japan’s defeat.

Legacy: The Submarine Force’s Enduring Impact

The Pacific submarine campaign left profound legacies:

– Established submarines as capital ships rather than auxiliary vessels
– Demonstrated the strategic potential of commerce warfare
– Provided case studies in joint operations integration
– Influenced postwar naval architecture and doctrine
– Inspired generations of submariners with their courage and ingenuity

As Admiral Lockwood’s victory message to his submarines stated: “The courage, ability, initiative, determination and loyalty you displayed cannot be adequately expressed in words.” The silent service had roared when it mattered most, helping bring history’s most destructive conflict to an end.