After being transferred to the West Coast in May 1939, Helm engaged in fleet exercises and screening maneuvers out of San Diego and the Hawaiian Islands.

At 0755 on the morning of 7 December 1941, Helm had just turned into West Loch in Pearl Harbor, en route to deperming buoys,[1] when Japanese carrier planes attacked the naval base.

At 0817, through the flames and smoke, Helm left West Loch Channel and sped to the open sea through the Pearl Harbor Inlet.

After the attack, Helm joined the task group of carrier USS Saratoga, just arrived from San Diego, and served as a screening ship and anti-aircraft guard.

Following a round trip voyage to San Diego, Helm departed Pearl Harbor 15 March 1942, escorting an advance base party to the New Hebrides.

Following practice landings Admiral Turner's fleet suddenly struck Guadalcanal and Tulagi, arriving off the beaches on 7 August and catching the Japanese completely by surprise.

Failures in search and identification had prevented early analysis of the dangerous situation, and the inadequate two-ship screen off Savo Island had not warned of the Japanese ships.

On 15 May 1943, Helm assisted in the search for survivors from the Australian hospital ship Centaur that had been torpedoed and sunk by Japanese submarine I-177, south east of Cape Moreton, near Brisbane.

As MacArthur's army prepared to move into New Britain under naval cover, Helm bombarded Gasmata on 29 November 1943 and sortied from Milne Bay again on 14 December under Admiral Crutchley for the capture of Cape Gloucester.

Helm helped in the pre-invasion bombardment, fired close-support missions after the initial landings, and performed screening duties as transports unloaded.

The carrier task forces returned from a strike on the Bonin Islands on 18 June and deployed to repel the Japanese fleet as it closed the Marianas for a decisive naval battle.

As four large air raids hit the American fleet formation, fighter cover from Helm's task group and surface fire from the ships annihilated the Japanese planes.

With able assistance from American submarines, Mitscher succeeded in sinking two Japanese carriers while inflicting such staggering losses on the enemy naval air arm that the battle was dubbed the "Marianas Turkey Shoot."

Following the decisive Battle of the Philippine Sea, Helm and the fast carriers turned their attention to neutralizing the enemy bases on the Bonin and Volcano Islands and supporting the invasion of Guam.

Helm and companion destroyer Gridley made a contact around noon and, as the carriers cleared the area, the two ships dropped depth charges and sank I-46.

Arriving two days later, the ship began preparations for the next important amphibious operation in the Philippine campaign, the landings at Lingayen Gulf on Luzon.

The carrier groups were hit repeatedly by desperate air attacks, with Helm and the other destroyers accounting for many suicide and torpedo planes.

When escort carrier Bismarck Sea was sunk in a suicide attack on 21 February, Helm rescued survivors and brought them to the transport anchorage next day.

Sailing on 27 March, she joined escort carrier groups off the island for pre-invasion strikes; and, after the historic assault on 1 April, for ground support operations.

During her stay off Okinawa the destroyer shot down many suicide planes which menaced the carriers during fanatical, last-ditch efforts by the Japanese to repel the invasion.

Following the Okinawa operation Helm served as an escort and patrol ship out of Ulithi and Leyte, and helped to search for survivors of ill-fated Indianapolis from 3 to 6 August 1945.

Helm was used that summer as a target ship during the historic Operation Crossroads atomic tests in the Pacific, and her hulk was sold to Moore Dry Dock Co., Oakland, California, in October 1947 for scrapping.