On March 29th, 1944 USS Parche (SS-384) slipped out of Pearl Harbor with USS Tinosa (SS-283) and sister ship USS Bang (SS-385) for her first war patrol. The trio was to operate together as a wolf pack under the command of Captain G.E. Peterson, who was riding the Parche. After topping off on fuel oil at Midway, the three submarines reached the sea lanes south of Formosa. The first contact made was a derelict trawler, evidently the victim of another steely eyed killer of the deep. The Parche took the opportunity to sharpen her 20mm gun crews with a practice run and then continued her course reaching the assigned area on the 16th of April.

The next day a bird was attracted to the periscope with the following entry in the ships log:

On April 29th, the USS Bang reported a large convoy 50 miles away. Running on a full bell for three hours the Parche sighted one large ship with a single escort. Another escort came into view as the Parche, on the surface, began running around the target. The escort immediately gave chase. The sub, having about a half-knot speed advantage shook the escort off after 20 minutes but lost track of the convoy.

The USS Bang put Parche back on track again at 0350 on April 30th, as the convoy was pinpointed by a column of flame on the horizon. An enemy ship was engulfed in flames from one of the Bang’s four torpedo hits. By 0513, Parche was in position to count ten ships in the convoy, but the on-coming dawn forced her to break off an attempted surface attack to begin an end-around approach.

Finally at 1010, the sub was again in a firing position and launched four torpedoes, two each at the two lead ships in the starboard column. The enemy apparently sighted Parche’s periscope at the time of firing and hoisted a two-pennant signal and turned to avoid. Disappointed, Captain Ramage took the boat down from periscope depth to avoid bombing by the convoy’s air cover. A timed hit was heard however, and later the Bang reported that one of Parche’s torpedoes went on past the target and hit a ship in the other column. The Tinosa attacked, scoring several hits before losing contact.

On the morning of May 3rd the Tinosa reported a seven-ship convoy at 20-48N, 118-03E so Parche headed north at full speed to intercept. After performing several maneuvers around the convoy she was again picked up by a patrol boat and chased for an hour and a half. After evading the patrol boat Parche began to get back into a firing position. The sonar operator reported hearing distant explosions indicating that Tinosa and Bang had taken advantage of the lessened escort.

An hour after midnight Parche was in position and fired four torpedoes, scoring three torpedo hits on the leading freighter, the Shoryu Maru, a 6,475 ton cargo vessel. The ship appeared to "blow up," break in two, and sink almost immediately. Parche also fired two torpedoes at the second freighter, the Taiyoku Maru, a 5,244 ton  scoring two hits and sinking it too. The third freighter began to maneuver wildly and began firing her deck guns at random as the second freighter was sinking. Her evasive maneuvers did no good, however, for at 0127 Parche fired four torpedoes scoring two hits, one amidships and one aft, blowing out the after mast. The third freighter was settling by the stern and began to list to port while Parche hauled clear to reload. Then the Bang came in for the kill resulting in the loss of another cargo ship to the Japanese Empire.

Parche, now fully reloaded began to set up for another attack. Unfortunately the moon broke out from behind the clouds, which then silhouetted her on the surface exposing her to an escort. The escort, which had superior speed began to give chase, but fortunately Parche was able to lose her by ducking into a rain squall. The Tinosa, meanwhile was mopping up by sinking two AK’s (armed amphibious transports) and damaging two other ships, leaving only the escorts searching aimlessly for three American submarines that were now just a fatal memory. Post-war records credited the trio of submarines with five ships sunk and 30,542 tons, Parche getting credit for three cargo ships.

On May 5th the Bang and Tinosa were both out of torpedoes and were ordered home while Parche remained on station making a thorough photoreconnaissance of military installations on the island of Ishi Gaki Jima.

On May 19th a trawler crossed her track and Parche made three attack runs with her with automatic weapons. Parche was unable to sink her due to poor visibility and the necessity to get out of a restricted area which forced her to break off. Total tonnage for Parche's first war patrol was 30,400 tons.