In April, she moved to San Diego and conducted flight training operations, after which she rendezvoused with Task Group 51.1 and steamed for Cold Bay, Alaska with Composite Squadron 21 (VC-21) embarked.

Nassau got underway on a search mission 4 May and conducted flight operations with Task Force 51, providing air cover for the occupation of Attu Island from 11 May through 20 May.

She returned to San Diego in late May, arrived at Alameda 8 June and onloaded 45 aircraft destined for Brisbane, Australia.

Returning to San Diego from Samoa, 19 October, Nassau embarked Marine Fighter Squadron 225 (VMF-225) for passage to Pearl Harbor.

As a result, VF-1 was assigned combat air patrol and flew bombing and strafing runs from the carrier in support of the assault troops.

The squadron flew a total of 106 missions and spent 237 hours of flying time in four days of operations without losing a single plane or pilot.

She then sailed to the Marshall Islands with Task Group 51.2 and launched strikes 29 January 1944 against Taroa Field on Maloelap Atoll.

The next day, the Task Group centered its operations around Kwajalein, Wotje, and Maloelap Atolls, with Nassau conducting both anti-submarine and combat air patrols.

Steaming in company with the oiler groups, which refueled the ships of the Task Force at sea, Nassau made three cruises into the western Pacific.

Steaming to Ulithi Atoll in the Caroline Islands, she joined up with Task Groups 38.1 and 38.3 on 28 October and transferred 70 aircraft and 43 pilots to the attack carriers.