The Strategic Shift in Pacific Submarine Warfare

As 1945 dawned, the U.S. Pacific submarine fleet underwent a dramatic transformation. No longer operating as isolated hunters, American submarines now functioned as integrated components of larger naval campaigns. The shrinking perimeter of Japanese-controlled waters—thanks to relentless advances by U.S. Army and Marine Corps forces—forced submarines into closer coordination with surface fleets. This strategic evolution coincided with Japan’s desperate attempts to maintain maritime supply lines despite catastrophic shipping losses.

The relocation of the Pacific Submarine Force headquarters from Pearl Harbor to Guam in January symbolized this shift. Admiral Charles A. Lockwood’s decision to establish forward command aboard the tender USS Holland reflected the need for real-time decision-making as operations intensified near Japan’s home islands. This move placed submarine commanders closer to critical battle zones like Iwo Jima and Okinawa, where photographic reconnaissance and lifeguard missions for downed aviators became paramount.

Three Critical Missions for Victory

Submarine operations in early 1945 focused on three specialized tasks that would prove decisive in the war’s final months:

1. Technological Adaptation: The rushed deployment of classified equipment like FM sonar and the “Curry” anti-escort weapon system. These innovations aimed to counter Japan’s improved depth-charge tactics and save countless submariner lives.

2. Aviator Rescue Protocols: Enhanced coordination with bomber commands to retrieve downed pilots. Submarines had already rescued 140 airmen between 1943-1944, but new radio technologies promised higher survival rates during the intensified bombing of Japan.

3. Minefield Penetration: Developing techniques to breach Japan’s defensive mine barriers—a prerequisite for the eventual invasion of the Home Islands. This included perilous mapping missions near Okinawa, where submarines like USS Swordfish disappeared while gathering intelligence for upcoming amphibious assaults.

The Human Cost of Naval Innovation

The transition to new warfare methods came at a price. The accidental sinking of the salvage vessel USS Extractor by the submarine USS Guardfish in January revealed systemic communication failures. Three officers—the captains of both vessels and Guam’s operations commander—shared blame for the friendly-fire incident that killed six sailors. This tragedy underscored the fog of war even as technological advantages grew.

Meanwhile, submarine crews faced unprecedented dangers in shallow coastal waters. The legendary USS Barb (SS-220) executed one of the war’s most audacious attacks in February, infiltrating China’s Namkwan Harbor disguised among fishing junks. Commander Eugene Fluckey’s daring surface attack destroyed multiple anchored ships, earning the Barb a Presidential Unit Citation. Such operations demonstrated how submarine warfare had evolved from open-ocean patrols to daring coastal raids.

Turning Points and Tragedies

February 1945 witnessed both triumph and heartbreak. The USS Batfish (SS-310) achieved an unmatched feat—sinking three Japanese submarines (I-41, RO-112, and RO-113) in 76 hours during patrols near Luzon. This remarkable success contrasted with the loss of USS Barbel (SS-316), likely destroyed by Japanese aircraft while operating in the treacherous Balabac Strait.

The month also saw innovative “wolfpack” tactics deployed around Iwo Jima. Groups like “Mac’s Mops” and “Latta’s Lancers” used new deck guns and proximity-fused ammunition to clear Japanese patrol boats, paving the way for the February 19 amphibious assault. These operations marked submarines’ full integration into combined-arms warfare.

Legacy of the 1945 Campaigns

The Pacific submarine fleet’s final campaigns redefined naval warfare. By war’s end, U.S. submarines had:
– Sunk over 1,300 Japanese merchant ships (55% of all tonnage lost)
– Destroyed 214 warships including battleships and carriers
– Rescued 504 downed aviators (including future President George H.W. Bush)

Perhaps most significantly, the 1945 operations demonstrated how specialized submarine warfare had become—from mine detection to electronic intelligence gathering. These hard-won lessons would shape Cold War undersea strategies and cement the submarine’s role as America’s silent sentinel in the nuclear age.

The courage displayed by crews like those of Barb, Batfish, and the ill-fated Swordfish remains etched in naval history. Their stories—of innovation under fire and sacrifice in war’s twilight—continue to inspire modern submariners who patrol the same Pacific waters their predecessors helped liberate.