The Balao-class submarine was the backbone of the United States Navy's underwater fleet.

Wars & Conflicts · Published 15 October 2026 · Updated 25 October 2026 Swipe more like this →

In short: With 120 boats completed, the Balao class stands as the most numerous submarine design in United States history. Engineered for deep-sea endurance during World War II, these vessels evolved through constant combat feedback and postwar modernization, serving globally for decades and proving their versatility in both war and cinema.

The Balao class emerged as a refined successor to the Gato-class submarines. Designers Captain Andrew McKee and Commander Armand Morgan sought to improve diving capabilities by utilizing a high-tensile steel alloy and thicker hull plating. While initial plans targeted a test depth of 450 feet, limitations in the existing trim pump technology led Rear Admiral E. L. Cochrane to cap the official test depth at 400 feet. Despite this, the class proved remarkably resilient; the USS Tang famously exceeded its depth gauge's maximum reading of 612 feet while evading a destroyer in 1944.

Combat performance defined the class's legacy. These submarines were instrumental in the near-total destruction of the Japanese merchant fleet and inflicted significant losses on the Imperial Japanese Navy. The USS Tang remains the highest-scoring vessel of the class, credited with sinking 33 ships. Another notable success occurred when the USS Archerfish sank the aircraft carrier Shinano, which remains the largest warship ever destroyed by a submarine. The class also featured in popular culture, with the USS Redfish portraying the fictional submarine in the 1958 film Run Silent, Run Deep.

Postwar, the class underwent extensive modernization to remain relevant against newer, more advanced threats. Programs like GUPPY and Fleet Snorkel introduced snorkels, streamlined sails, and upgraded battery systems to mimic the performance of German Type XXI U-boats. These modifications allowed many boats to remain in active service through the 1970s. Beyond the US Navy, 46 of these submarines were transferred to allied nations, with one vessel, the former USS Tusk, continuing to serve in the Republic of China Navy as the Hai Pao.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• Launched exactly one year after Pearl Harbor, the USS Bowfin became its avenging submarine.
• Why the US Navy stopped naming its deadliest submarines after marine animals
• The heavy, noisy Soviet submarines that defined the Cuban Missile Crisis
• The Swiftsure-class submarine redefined stealth and power for the Royal Navy in the 1970s
• The largest warship ever sunk by a submarine was a secret, unfinished Japanese carrier.
• Before the 19th century, most battles were over within a day
• Beyond the uniform: how the U.S. military tracks service through medals and ribbons
• The Battle Dress Uniform defined the look of American soldiers for over two decades.
• Is attrition warfare a brilliant strategic choice or just a rationalization for failure?
• How Daniel Morgan turned a tactical weakness into a brilliant Revolutionary War victory
• From makeshift biplanes to high-tech gunships, how helicopters became the ultimate tank killers.
• How a single minefield halted a German Panzer charge in Tunisia

More in War and military · More in Wars & Conflicts · Latest · A–Z · All topics