Sasha Cooper is a former Navy Intelligence Officer now operating under diplomatic cover in China for the newly reformed United States government.
A recurring theme in The Last Ship is that Sasha is able to understand and speak whatever language is necessary at the time, due to the large number of languages in which she is fluent. Sasha is known to be fluent in the following languages:
In the series finale, Sasha is one of the few still-living characters with whom Tom had served, who appears in his hallucination as he is drowning, after Nathan James sinks ramming Gustavo's Battleship in order to end the war with Gran Colombia. Tom views, and then is part of, an award ceremony for him, which also serves as a change of command ceremony for Nathan James. When President Michener asks Tom if he is ready to be relieved (as commanding officer,) Tom hesitates and wonders aloud who he is passing responsibility onto. After many of the sailors sitting in the audience for the ceremony (who are also Tom's close friends and allies,) stand and declare that they have the watch, Tom is finally able to achieve peace and be able to mentally and emotionally let go of both Nathan James, and of the burdens he has carried around since the plague began, secure in the knowledge that others will always be there.
Ultimately, Tom decides to keep fighting, swim to the surface, and live.