I think an umbrella stroller would be fine in the vast majority of those cities from the little I know of them. We have cruised a lot in the last year and a half with our two little ones aged 3 and 6. It has been great, but one of the things that we have found is that if it doesn't involve a beach, a pool, zoo or an aquarium, its really tough to get them off the ship, since they are completely addicted to Camp Carnival. Not that you asked, but one thing I have found with our kids is to take them out for sightseeing and excursions that are not on their "A list" for only a few hours then allow them to return to Camp Carnival when they are ready, otherwise they get bored, whiney and no one has any fun. Camp Carnival is wonderful for port days when the kids don't want to do "grown up" stuff and they've always done a lovely job in making our kids cruises very special.