Following a month of shakedown training along the east coast, the submarine departed New London, Connecticut, and headed south to join the action in the Pacific.

After transiting the Panama Canal, Atule steamed to Pearl Harbor with Jallao, training intensively en route to reach a peak of combat readiness.

The pack arrived at Tanapag Harbor, Saipan, on 21 October, refueled, made minor repairs, and departed early the next day.

Atule continued her patrol, covering the Hong Kong-Manila traffic lane in the South China Sea and occasionally breaking off to investigate a contact report or to take special scouting dispositions by order of the pack commander.

Later that day and throughout the next, the submarine played a game of hide and seek with Japanese planes equipped with radar and magnetic detection devices.

After a circuitous route to avoid Japanese planes, Atule began patrolling her assigned scouting station west of Formosa.

The enemy, identified later as Minesweeper Number 88, was protected by a squall during the early phase of Atule's approach, but was perfectly silhouetted against a clear horizon when the submarine fired four torpedoes.

The escort, later identified as Patrol Boat Number 88, was claimed destroyed but survived the attack;[9] and the transport, a 7,266-ton cargo ship named Santos Maru, went dead in the water.

Atule spent December in upkeep and training, including a six-day coordinated convoy exercise with Spadefish, Pompon, and Jallao.

En route to Saipan, "Underwood's Urchins" conducted training dives, emergency drills, and radar tracking exercises.

Atule patrolled the Chinese and Korean coastlines and traffic lanes until 22 February, when she headed for Saipan where she once again moored alongside Fulton.

After refit alongside Pelias, Atule conducted extensive drills in multiple fire torpedo attacks, gunfire, sound training and evasion exercises.

After nine days with little action, the submarine proceeded to her patrol area in Empire waters east of Honshū as part of an attack group which also included Gato and Archer-Fish.

Shallow waters and poor visibility caused Atule to set a course to intercept in the vicinity of Urakawa Ko rather than to attack the contacts under such adverse conditions.

In company with Norton Sound, Whitewood, Alcona, Beltrami, and Northwind, Atule was to transport supplies and passengers, conduct reconnaissance of proposed weather station sites, train personnel, and collect data on Arctic conditions.

Following engine trouble, the Catalina made an emergency landing, and Atule was dispatched to recover the plane, becoming the first ship of the operation to enter the harbor.

[11] On 29 July, Atule departed Thule, having completed all of her scheduled projects, stopped at Halifax, Nova Scotia and reached New London late in August to resume her former duties.

After three years in "mothballs," Atule was towed to the Portsmouth Naval Shipyard in Kittery, Maine, for reactivation and conversion to a GUPPY IA type submarine.

Outfitted with a snorkel to permit use of her engines while submerged and a smooth streamlined superstructure for added speed, Atule rejoined the fleet a stronger, more versatile warship.

During this operation, she found herself battling the high seas and 100 kn (190 km/h) winds of Hurricane Charlie which at one point rolled her more than 60 degrees to port, washing the officer of the deck and the lookout off the bridge.

But for a two-week visit to the Fort Lauderdale, Florida, area to provide services to the Naval Ordnance Laboratory Test Facility, she remained in New London for five months.

Upon her return to New London Atule operated in the local area until February 1955, when she entered the Philadelphia Naval Shipyard for an extensive overhaul which was completed in August.

In July 1960, Atule again cruised to the Mediterranean Sea for surface-subsurface training with NATO forces which lasted until October, when she returned to the United States and entered the Charleston Naval Shipyard for a six-month overhaul.

After completion of the yard work in April 1961, Atule spent 18 months alternating duty at Key West, Florida, with service at Guantanamo Bay supporting training for the destroyer force in antisubmarine warfare.

In August 1965, Atule departed Port of Spain, Trinidad, in company with other United States warships for a goodwill cruise during which she circumnavigated the South American continent.

Atule drilled with ships of the navies of Venezuela, Colombia, Ecuador, Peru, and Chile as she transited the Panama Canal and headed south along the coast.

As she headed north, Atule's crew became ambassadors of good will in port calls to Puerto Belgrano, Mar del Plata, Rio de Janeiro, and San Salvador before disbanding the UNITAS VI task unit in Trinidad on 1 December.

The submarine returned via St. Petersburg, Florida, to her home port, where she continued general operations until 1 October when she got underway for her last Mediterranean Sea deployment.

Redesignated with the hull classification symbol AGSS-403 on 1 October, Atule was decommissioned on 6 April 1970 and her name was struck from the Naval Vessel Register on 15 August 1973.

Renamed BAP Pacocha (SS-48), the submarine served in the Marina de Guerra Peruana (the Peruvian Navy) until 26 August 1988, when she was rammed and sunk by a Japanese fishing trawler.