 Soon after her commissioning in November 1955, "Thrush" arrived in Chesapeake Bay to conduct a successful shakedown cruise.In 1956, she was assigned to the Yorktown, Virginia, Mine Warfare School, followed in August by assignment to Norfolk, Virginia, to participate in Operation Hideaway.In 1957, "Thrush" moved to her new homeport in Key West, Florida, where she tested and evaluated new mine warfare equipment for the 6th Naval District's Mine Warfare Evaluation Detachment.