Nine of Finback's twelve World War II patrols in the Pacific were designated as "successful"; she received 13 battle stars for her service and is credited with having sunk nearly 70 thousand tons of enemy shipping.

Finback reached Pearl Harbor from New London on 29 May 1942, and two days later, with the Japanese fleet on the move, was ordered out to patrol during the Battle of Midway.

Crewmate (Electrician's Mate, 2nd class) Robert D. White recalls the event, "They [a Japanese ship] fired depth charges at us for nearly twenty-four hours.

Just as 'Skip' started talking about surrendering for lack of oxygen, the charges stopped...Fresh air never felt so good as when we made it to the surface and opened the hatch.

The submarine launched two torpedoes at each of the two largest targets, sinking one, the ex-French merchantman Ville De Verdun, rechristened the Teison Maru (7007 tons), returning empty to Japan, and went deep for the inevitable depth charging.

Later, she engaged the Japanese coaster Yachiyo Maru (271 tons) in a surface gun duel on 17 January, leaving the enemy craft abandoned and sinking.

After refitting at Midway, Finback made her fourth war patrol between 27 February and 13 April, scouting shipping lanes between Rabaul and the Japanese home islands.

On 5 April, passing a reef south of Japanese-held Wake, Finback sighted the troop transport Suwa Maru, beached and well down by the stern.

She sank the tanker Isshin Maru (10044 tons) in a surface attack on New Year's Day 1944, after it was unable to keep up with its convoy due to a rudder malfunction.

Prevented from launching attacks through most of the eighth patrol because of her assignment as lifeguard for carrier air strikes on targets in the Carolines, Finback contacted a six-ship convoy on 12 April, noting three escorts.

Watchman Torpedoman First Class Donnet Kohler pulled out a tall lanky young pilot who would later become the 41st President of the United States, George H. W.

[9] Pilot Beckman was rescued by holding on to the Finback's periscope until the partially submerged vessel was five miles from Haha Jima and out of shelling range of Japanese cannons.

The submarine's twelfth war patrol, made between 20 January and 25 March 1945 in the East China Sea, was frustrated by a lack of targets, and Finback returned to Pearl Harbor for a thorough overhaul.