 Immediately after commissioning, "Hydrographer" steamed to Newfoundland, where she spent the remainder of 1942 charting the approaches and harbor to the important Allied base at Argentia.She returned to the Norfolk Navy Yard 7 November 1942; and, after alterations to fit her for duty in the Pacific, sailed 30 December for San Diego, via the Canal Zone.The survey ship got underway 26 February 1943 for Atka Island, in the Aleutians, and arrived 22 March to carry out a survey of Korovin Bay, in preparation for the spring offensive to come.