in Washington and Esquimalt, British Columbia, Canada, until returning to San Diego, which once again became her home port, in July 1978. From her return to San Diego until April 1979, Drum completed the rigorous training, testing, and loadout necessary prior to a deployment. She then deployed to the Western Pacific again from May to October 1979. During this deployment, she completed a special operation for which she was awarded her second Meritorious Unit Commendation and made port visits to Guam, Thailand, and the Philippines. After returning to San Diego in October 1979, she engaged in local operations and completed two months of repairs and alterations at Mare Island Naval Shipyard. 1980s In May 1980, after Drum returned to San Diego, and for the next several months, Drum operated in the San Diego area. She began her next Western Pacific deployment in October 1980, which included visits to Guam and the Philippines. This deployment lasted until mid-April 1981, when she returned to San Diego. In the course of that year the collided with an unidentified American submarine, believed to be of the , in the Peter the Great Bay, not far from Vladivostok. At least one source identifies this submarine as USS Drum. In November 1981, Drum again departed San Diego for the Western Pacific, visiting South Korea, spending Christmas in Japan, and returning home at the beginning of 1982. She then conducted operations off Southern California and visited San Francisco, California, before starting another period of repairs and alterations in San Diego in the summer of 1982. Upon completion of repairs, Drum concluded 1982 preparing for her next deployment. Shortly after Christmas 1982, Drum deployed to the Western Pacific. During this deployment, Drum visited the Philippines, Australia, and Japan, and also conducted operations in the Indian Ocean, during which she visited Diego Garcia. She returned to San Diego in June 1983. After a routine standdown period at the end of this deployment, Drum participated in Advanced Capability (ADCAP) Mark 48 torpedo testing exercises at the tracking range at Canadian Forces Maritime Experimental and Test Ranges, Nanoose Bay, British Columbia. In May 1984, Drum left San Diego for a Western Pacific deployment, stopping in Hawaii for RIMPAC '84, a multi-national naval exercise, then continued west with visits to the Philippines, Japan, Guam, and Thailand. Drum returned to San Diego in November 1984. 1985 began with local operations off Southern California