What? A large ship needs a tug boat to get in and out of the harbor...? Hmph....So at the Naval Base, the Admiral is acting as the tugboat and pushing Eugen out to sea?.... Hmmm...Is it needed for us the shipgirls? ...Hey?Tug/Tugboat
A boat or ship that maneuvers large vessels by pushing or pulling them through constricted bodies of water. Tugs also help tow vessels that are not able to move by themselves.
literally just the definition of a tugboat