Yes, a stroller is considered a carryon for the child who uses it. We try to bring luggage that fits inside one another when stored as we'd hate to have luggage all over our stateroom for a week! I find that clothes bags and soft duffelsare easier to store than large suitcases (if they are too big to fit under the bed. )You can get particularly cramped if you have to leave a port a crib up most of the time.