USS Robalo, a 1525-ton Gato class submarine, was built at Manitowoc, Wisconsin. She went into commission in late September 1943 and transited to the Pacific during the last part of that year. Her first war patrol, during the first months of 1944, began at Pearl Harbor, Hawaii. It produced no sinkings and terminated at Fremantle, Australia. Robalo left Fremantle in April 1944 to conduct her second patrol, this time targeting Japanese tanker traffic in the South China Sea. Her new Commanding Officer, Manning M. Kimmel, attacked several ships and was credited at the time with sinking one, though postwar review failed to confirm this. In return the submarine was near-missed by enemy bombs that damaged her periscopes. Repaired after returning to Fremantle, she left for another patrol in June, en route back to the South China Sea. On the night of 26 July 1944, while passing through the Balabac Strait, near Palawan, she apparently struck a mine and quickly sank. A few of her men swam ashore and were captured by the Japanese. However, either due to deliberate action by the enemy or through the hazards of war, none of Robalo's crew survived to the end of the conflict.