From the back cover:
Fleets of starships vie for dominance among the pocket empires and the growing Sylean Empire. Imperial Squadrons sets the stage for Traveller play on the flagships of enormous space fleets, drawing resources and conquering worlds. Complete guidelines for role-playing while still in the service, adventuring in the midst of battles that decide the fate of millions!
From the Introduction:
Imperial Squadrons explores the role of fleet units in the Traveller universe. Through their characters, players will design, battle, finance, and crew squadrons. Players will step into the role of naval architects, military strategists, squadron leaders, or even fleet admirals and engage each other in battles fought in the context of rival Pocket Empires.