If you haven't been to Seatle in a while, you'll find that the waterfront has changed considerably: very walkable, revamped aquarium, etc. My grandson is an airplane/space nut, so I've been to the factory and the Air museum numerous times. I think the children would much prefer the Air Museum. It's more interactive, volunteer ex-Boeing people on hand to answer questions and share knowledge. Easy to uber there from downtown hotel. Everett is further, with horrendous traffic at times. The Seattle Science Center @ Pacific Center is also excellent.

@bbstx We made a noon flight. However, there were only two ships in port that day, so on a day with four it could get worse.

Oh, dear. Maybe I ought to get a car and driver to meet us. I just checked. 4ships docking in Seattle at the same time!!!