Following shakedown in the New London and Newport, Rhode Island, area, Angler sailed to Key West, Florida.

Having developed "structural noises" which prevented silent running, Angler turned back to Midway Island for repairs, arriving on 4 February.

While she was nearing her patrol area, General Douglas MacArthur had learned that the Japanese were massacring all the civilians they could find on the island of Panay.

Angler sailed on 3 May for another patrol as one of eight submarines assigned to support the Operation Transom carrier strike scheduled to hit Surabaya, Java.

Their job would be to sink retreating Japanese ships, to provide lifeguard services, and to guard the major passages from the Java Sea (the Sunda Strait and Lombok Strait) to the Indian Ocean lest the Japanese try to move into the Indian Ocean to attack the Allied strike force.

On 22 May, Lieutenant Commander Olsen noted in the log: "Physical condition of officers and crew is so bad that it is difficult to maintain watch, either surface or submerged.

She paused to refuel alongside a barge in Exmouth Gulf on 24 June, and while maneuvering into position, hit an uncharted obstruction.

On 25 July, Angler and her sister ships picked up a large northbound convoy and began a series of attacks over the next few days.

[citation needed] At 0145 on 22 October, the men on watch on Angler's bridge were startled by voices calling out of the darkness.

Repeated attempts to locate the source of the voices proved unsuccessful, but the dawn soon revealed "one of the most gruesome sights imaginable as far as you could see ..." the water literally covered with wreckage and dead Japanese, most clad in Army uniforms.

At 1915 on 23 October, Angler made radar contact with the main Japanese force steaming to contest the Allied invasion of Leyte.

A shell tore a large hole in Bergall's pressure hull and left the submarine unable to dive.

Angler, operating in the Java Sea, received orders to proceed to Bergall's assistance, take off the crew and torpedo the ship.

The two submarines traveled nearly 2,000 nmi (3,700 km), through waters mostly controlled by the enemy, and reached Exmouth Gulf safely on 20 December without seeing any Japanese airplanes or ships.

Angler reached the West Coast of the United States on 24 February, and immediately began overhaul at the Bethlehem Steel Company yard at San Francisco, California.

One of these moved away faster than Angler could close, but the submarine developed the other into an unsuccessful torpedo attack on 25 July.

From a range of about 3,000–4,000 yd (2,700–3,700 m), Angler hurled 25 5 in (130 mm) rounds at a target area containing closely bunched buildings, radio towers, and a lighthouse.

Although she claimed at least 20 hits, the large clouds of smoke and dust made a closer assessment of damage impossible.

In October 1952, Angler was decommissioned and entered the General Dynamics Corporation yard at Groton, Connecticut, for overhaul and conversion.

During the overhaul, one of her four diesel engines was removed to make room for advanced sonar equipment, part of her conversion to a "hunter-killer submarine".

She then operated along the East Coast and in the West Indies for the next two years, taking part in numerous Atlantic Fleet exercises, and spent the period from January through April 1956 undergoing overhaul at the Portsmouth Naval Shipyard.

From 24 February-23 March 1958, Angler participated in Operation "Springboard," held in the West Indies and Caribbean, following those evolutions with numerous training exercises.

Sold to the Union Minerals and Alloys Corporation, of New York City on 1 February 1974, she was removed from naval custody on 4 March 1974 to be broken up for scrap.