After shakedown, Helm operated in the Caribbean until March 1938. Following summer exercises, she was attached to the newly formed Atlantic Squadron 1 October 1938. Early in 1939, she deployed with Carrier Division 2 in the Caribbean for the annual fleet problem, developing tactics and doctrine so vital in the war that was to come. Transferred to the West Coast in May 1939, Helm engaged in fleet exercises and screening maneuvers out of San Diego and the Hawaiian Islands. This duty continued through the troubled months of 1941, and on the morning of 7 December, Helm was underway in West Loch Channel, Pearl Harbor when the Japanese planes struck. The destroyer manned her guns and brought down at least one of the attackers while she was strafed and slightly damaged by two bombs close aboard. After the attack, she joined the task group of carrier Saratoga just arrived from San Diego and served as screening ship and plane guard.
The destroyer sailed 20 January on a special mission to rescue Department of the Interior workers from Howland and Baker Islands. Using her whaleboat, Helm brought off six men from the two islands 31 January. She was attacked by a Japanese patrol bomber later that day. Her gunners drove off the attacker and the ship returned to Pearl Harbor 6 February.
Following a round trip voyage to San Diego, Helm departed Pearl Harbor 15 March escorting an advance base party to the New Hebrides. She arrived Éfaté 19 March and for the next few weeks escorted ships in that area while U.S. bases were consolidated. She rescued 13 survivors from SS John Adams on 9 May and 4 from oiler Neosho, sunk in the Battle of the Coral Sea on 17 May. These men were taken to Brisbane, Australia, where Helm joined British Rear Admiral Crutchley’s Task Force 44 on 19 May.
For the next two months, Helm performed escort duty along the Australian Coast. The fleet was then assembling for the first offensive amphibious operation in the Pacific, the capture of Guadalcanal. Helm departed Auckland, New Zealand, 22 July for the Fiji Islands. Following practice landings Adm. Turner’s fleet suddenly struck Guadalcanal and Tulagi, arriving off the beaches 7 August and catching the Japanese completely by surprise. The destroyer screened the transports as troops disembarked, shooting down several attacking aircraft during the first two days.
With cruisers Vincennes, Quincy and Astoria, Helm patrolled the waters around Savo Island the night of 7 August and, as night fell 8 August, the four ships and destroyer Wilson took up patrol between Savo and Florida Islands. Another group of two cruisers and two destroyers patrolled to the south, and picket destroyers Blue and Ralph Talbot were stationed to the northwest of Savo Island. A fateful combination of circumstances had allowed Admiral Mikawa’s cruisers and destroyers to approach Savo Island undetected. 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. The alarm was sounded by destroyer Patterson at about 0143, just seconds before two torpedoes ripped into HMAS Canberra in the southern group soon both formations of cruisers were battling the fierce Japanese attack. Helm, on the port bow of Vincennes, turned back to help the stricken cruisers. She stood by Astoria, brought survivors to transports off Guadalcanal and withdrew with the remainder of the force to Nouméa 13 August. The Battle of Savo Island was a disaster, but even in defeat, the ships had prevented the Japanese from attacking the vulnerable transports at Guadalcanal. Much desperate fighting followed but the Americans had come to stay. (continued)