On 17 September, now in the hands of Reuben Whitaker, "S-44" began her fourth war patrol. The following day, a hydrogen fire blazed in her forward battery compartment, but was extinguished in three minutes. On 22 September, she began surfacing only at night, and, two days later, took patrol station off New Georgia to interdict Japan's Faisi-Guadalcanal supply line. During the patrol, her hunting was hindered by Japanese aerial and surface antisubmarine patrols and her own operational capabilities, which were further limited by material defects and damage inflicted during depth chargings.