Thanks, unfortunately we are going to visit our D the last week of March. I thought maybe we could try and visit on Easter Sunday, maybe it would be less crowded :/
No young children, just adults who like aquariums.
From their site:
From September 7, 2012, through March 22, 2013, admission to the National Aquarium, Baltimore, is just $12 on Fridays after 5 p.m. Last entry time is 8 p.m., and you can tour the exhibits until 9:30 p.m. Blackout dates apply. Add on a 4D Immersion Film for just $5.
I don't know if this fits your schedule, but it really was the best time to visit, often we felt like we had the place to ourselves.
The dolphin show used to be really great but I think that they stopped doing those.
We saw the dolphin show last month.