I have not een to the San Diego port so I can only give you my plan of action when cruising with out children. When you receive you cruise booklet, the front cover will tell you when the ship debarks and when the terminal is open. When it states the cruise terminal will open at 1:00 the people will arrive by the carloads by 10:00 am. You can your lunch for free on the ship by doing this as you will get on the ship earlier, but with kids, I'd rather pay for their lunch and avoid all that. If the ship leaves at 4:00, we arrive about 3:00. We find some place to eat, shop, relax, whatever, close to the ports, arrive an hour before debark, walk straight through the terminal and up to the desk. I won't promise it's always this way, as I'm sure someone will prove me otherwise, but it has turned out this way for us every time. My parents, siblings, inlaws, aunts, everyone I know does it this way and has the same outcome. No waiting in one line for 30 min, then going upstairs another 30 min, standing in the 2 or 3 different snake lines for 1 hour. Kids just can't take that, It makes everyone grumpy, including other cruisers in line, who you have to see the rest of the week. Nobody likes to be known as "those people with the grumpy kids" LOL! Hope you have fun, I know you will.