Boarding is a bit easier than disembarking. I would arrive at the ship about an hour or so early. I know on our Carnival cruise, they started the boarding process a bit earlier than advertised, and we missed the rush. Getting off the boat can be a different story, but I have to imagine every experience is unique. Read my review of our Inspiration cruise in the Carnival section, which was probably on the end of the disembarking spectrum that you DON'T want. With kids, I would just make sure that your travel arragements leaving the port on your last day leave you with ample time to spare in case of delayed exiting off the ship. I would like to think that avoiding the cruisers that are wanting to be the first ones off the ship might be a good idea when travelling with young ones.