The Balao class was a successful design of United States Navy submarine used during World War II. An evolutionary improvement over the earlier Gato class, the boats had slight internal differences. The most significant improvement was the use of higher strength steel in the pressure hull, which increased their test depth to 400 feet.

General characteristics

• Displacement: 1826 tons surfaced, 2391 tons submerged
• Length: 312 feet
• Beam: 27 feet
• Draft: 15 feet
• Test Depth: 400 feet
• Speed: 20.75 knots surfaced, 8.75 knots submerged
• Armament: one three-inch/50-caliber gun, two 40mm cannon, six 21-inch torpedo tubes forward, four aft
• Crew: 75 – 80 officers and men
• Powerplant: four 6500-hp Diesel engines and four 2740-hp electric motors
• Range: 11,800 nautical miles at 10 knots surfaced