"Picuda", in wolf-pack with sister ships and , departed Pearl Harbor for her third war patrol 23 July in waters of the Luzon Strait between Formosa and Luzon. On 25 August, "Picuda" spotted ten ships hugging the coast some off the beach of Luzon. Slipping past five escorts, and with three enemy patrol planes overhead, she sent six torpedoes streaking to sink 1943-ton cargo ship "Kotoku Maru", then skillfully maneuvered for a down-the-throat shot that spelled the doom of 1270 ton pursuing . "Picuda" probed deeper in the interior of Luzon Strait on 16 September, for a bold daylight attack on an eight-ship convoy, guarded by three destroyers and air cover. She sank 5975-ton cargo ship "Tokushima Maru" and scored hits for unknown damage to two other freighters. Searching the southern border of her assigned patrol area, "Picuda" found another convoy hugging the north coast of Luzon on 21 September and sent 1948-ton freighter "Awaji Maru" to the bottom. "Picuda" made rendezvous with and , then set course in company with these two submarines to terminate her third war patrol in the lagoon of Majuro Atoll on 3 October.