Hi Eric!
Not answering your question, but an opinion 🙂
We spent a 10 day family vacation in Lisbon last year and I wouldn't recommend the aquarium if you only have one day in Lisbon.
The Oceanario is a nice aquarium, but nothing more than any aquarium you can see around the world. It is quite far from city center in a modern neighbourhood. If you do go, there is also a big American style mall with a large food court nearby.
However, Lisbon is such a beautiful historical city, IMO it would be a shame not to see it.
What I would recommend that we all loved (including kids) would be an tuk-tuk tour of the city. It was great fun to ride around and gives you an overview of the city. The guide will stop at the best spots, for as long as you like and act as your family photographer 🙂. I believe they can even pick you up from the cruise port. There might be other companies, but we used Tuk Tuk Tejo and were very satisfied.
Just an idea to consider 🙂
FYI, when we traveled last year, for the 4 of us it was cheaper to take an Uber than buy 4 metro tickets. I wouldn't bother with the public transit if you are a big group.
I hope you have a wonderful day in Lisbon, whatever you choose to visit 🙂