2 May. For her fourth war patrol, Stingray got underway on 27 May and headed for Davao Gulf, and then on to Guam. On the afternoon of 28 June, the submarine sighted two ships with escort, and quickly began to close the range. She fired four torpedoes at the first ship, and the resultant explosion quickly sank the converted gunboat Saikyo Maru. The submarine continued patrol in the vicinity of Guam until 15 July, when she returned to Pearl Harbor for overhaul. During that overhaul, she was fitted with two external torpedo tubes, just below deck level forward. Fifth through seventh war patrols Although Stingrays fifth war patrol, in the vicinity of the Solomon Islands, and sixth war patrol, conducted in the Marshall Islands, were unproductive, during the seventh, the submarine torpedoed and sank the cargo ship Tamon Maru. Eighth and ninth war patrols For her eighth war patrol, Stingray got underway from Pearl Harbor on 12 June 1943, and set course for the Caroline Islands. Her only contact during this patrol was a high-speed northbound convoy that she was unable to close on. The submarine returned to Brisbane, Australia, from a disappointing patrol on 31 July. On 23 August 1943, Stingray departed Brisbane for her ninth war patrol, conducted en route to Pearl Harbor. On 31 August, a United States Army Air Forces B-24 Liberator bomber attacked her as she crash-dived in the Solomon Sea west of Buka Island at , dropping three bombs which missed her by .. Stingray suffered significant damage but no casualties. She was forced to surface and repair the damage. She then patrolled in the Admiralty Islands without making a single contact and terminated her ninth patrol at Pearl Harbor on 10 October 1943, continuing on to Mare Island Navy Yard for shipyard overhaul. Tenth war patrol Following return to Pearl Harbor, Stingray got underway on 10 March 1944 for her tenth war patrol conducted in the Mariana Islands. On 30 March, she slipped past three escorts to gain attack position on two cargo ships, and fired four torpedoes at the lead ship. One torpedo hit amidships and stopped the enemy dead in the water. Stingray then fired four more torpedoes at the damaged cargo ship that quickly sent Ikushima Maru to the bottom. On the afternoon of 8 April, while patrolling north of the Marianas, Stingray bounced off a large submerged object at