What didn't you like about the Atlantis Aquaventure? We have booked it for June
I see you're from NN! I grew up in Gloucester and my family is still there
If you really want to do the Aquaventure, I would suggest grabbing a taxi as soon as the ship docks and going by yourself. When we booked the excursion, the 8:45 time was full so we had to do 9:45. I thought we were getting off the boat at that time, but 9:45 was just the beginning of a long process. We had to wait in line outside the Walt Disney Theatre and then show our tickets upon entering. Then we had to wait in another line to get our wristbands. Then we had to go sit down and wait to be called to leave the boat. Then we had to wait to catch a shuttle bus. Then when you get to Atlantis, you have to walk for like 20 minutes to even get to the waterpark. It was almost noon by the time we got there! And of course, all the loungers were taken so we had nowhere to leave our stuff.
I thought Atlantis was poorly run. It was a beautiful place with great potential. But after being on a Disney ship, you could tell the difference. The staff were not helpful, the bathrooms were extremely dirty, etc. Also, there was practically no signage and they had run out of maps. We couldn't find where anything was, nor did we know what was even available to do. Our son is 7 and was scared of a lot of the larger slides, but we could never find more kid friendly options b/c we didn't have a map!
There were 4 other ships in port that day, and the Aquaventure was packed! The lines were so long that we spent most of the day waiting. Also, they give you a voucher for lunch. There were 6 or 7 people in front of us in line, but it took at least 30 minutes just to get our food. They had the same person cashiering and getting the order together, and they wouldn't start taking the next person's order until the first person's order was complete. It was a terrible process and we wasted so much time just eating lunch.
We left at 4 to get back to the ship for our 5:45 dinner time. We could have certainly skipped dinner, but after eating in the dining rooms you won't want to!
So, my advice would be to get to Atlantis yourself so you'll have much more time. All the waiting burned a lot of the time we could have spent there. Also, print your own map before you get there. The only downside to this option is you do run a risk of it being sold out.