I love this restaurant. We always go in as soon as it opens at lunchtime (12pm) and have never been disappointed - always get a tank table. Just book a table at Guest services when you arrive in the morning. I'm not sure whether you can actually specify which table you get, which is why we are there when it opens.

I know that you've timed things for your visit, but if you are actually able to keep to those times it will be a miracle Nostromo, especially as you will have a number of people in your group. Living Seas and the Land are close together, so going back for lunch would only be a very short walk.