 Her paint scheme, raked masts and funnel, yacht-like stem, and cruiser stern gave her the appearance of a yacht or cruiser when her large fleet of boats were not stowed on deck.Upon her commissioning, "Explorer" toured ports in California in April 1940.She entered service in time to take part in the 1940 field season, during which she was assigned to conduct hydrographic surveys in the Aleutian Islands westward from Umnak Island with the smaller vessel "E. Lester Jones (ASV-79) assisting.