"New Jersey" began her career as a flagship 4 February in Majuro Lagoon when Admiral Raymond A. Spruance, commanding the 5th Fleet, broke his flag from her main. Her first action as a flagship was in Operation Hailstone, a two-day surface and air strike by her task force against the major Japanese fleet base on Truk in the Carolines. This attack was coordinated with the assault on Kwajalein, and effectively interdicted the Japanese naval retaliation to the conquest of the Marshalls. On 17 and 18 February, the task force accounted for two Japanese light cruisers, four destroyers, three auxiliary cruisers, two submarine tenders, two submarine chasers, an armed trawler, a plane ferry, and 23 other auxiliaries, not including small craft. "New Jersey" destroyed a trawler and, with other ships, sank the destroyer . "New Jersey" also fired on an enemy aircraft that attacked her formation. The task force returned to the Marshalls 19 February.