Monterey Bay Aquarium

We loved that aquarium.
I would go bright and early, as soon as it opens. Be there before the doors open, there have been lines around the corner to get in. I'm sure LAbor Day will be one of those weekends.
We used to go all the time, then we would go to the wharf and get clam chowder. It is just the best in the UNited States. She-crab soup in Swansboro NC holds a real close second.
We had yearly passes I found it well worth the money spent.

I think it'll be busy for sure, but if you can stay overnight (or don't mind returning home kinda late), the crowds start thinning out around 2 p.m. or so when the tour groups start heading back to the Bay Area in time for dinner so you'll be better able to see stuff in the afternoon. We typically arrive around noon and stay until closing time and the crowds have been manageable. We get a family membership b/c our kids like to go at least 2-3x during the year so the membership pays for itself

We went 2 yrs ago on Memorial Day weekend and I suggest you go to the MB Aquarium early, I would get there to get tickets well before they open. The weekend we went we expected smaller crowds due to the holiday, but were mistaken. THere was a line to buy tickets when they opened it was out the entrance door and up the street. We waited in line for tics about 30-40 minutes. When we got in the crowds were not too bad until mid-day then it got ugly and quite crowded. Some people in the crowds were rude and pushy mid-day.The whole aquarium takes hours to see everything, but is is well worth it and is a fantastic place. Keep this in mind if you go that weekend. If you have another choice of weekends I would recommend you change your plans, especially if your children are young. Ours was 12 and it was still trying for her (and my husband and me). Hope this helps.

it is gonna be crowded- I am convinced any weekend is- I would highly suggest ordering your tix on line if you can- Saves you time when you get there and cuts down the slowest line!