Back at Pearl Harbor on 18 January 1979, "Ashtabula" began eight months of underway training, local operations, and inspections. At the end of August, she embarked upon a six-week cruise to the west coast to conduct underway replenishment qualification trials and then participate in Exercise "Kernel Potlatch II," a joint United States-Canadian operation to test and evaluate plans for the common defense of North America. At the conclusion of the exercise, the oiler called at Esquimalt, British Columbia,on 6 October. After a three-day visit, she headed back to Hawaii on the 9th and arrived in Pearl Harbor on the 16th.