By the year 2380, Mariner had served on five Federation starships or starbases, including Deep Space 9 and the USS Quito and USS Cerritos, under command of Mariner's mother, Captain Carol Freeman.

During a viral outbreak stardate 57436.2, Mariner worked with the senior staff to secure the Cerritos. Later, she befriended the newly arrived Ensign D'Vana Tendi, and declared herself mentor of the command-track Ensign Brad Boimler. (LD episode: "Second Contact")