Here are the descriptions from Disneycruise.com. You can also check out
http://www.atlantis.com/atlantis_layers800.asp which is the web site for Atlantis for some other activites that are open to everyone. Personally I have not done any of the
DCL excursions to Atlantis, I find it easier to take a water taxi (or an actual taxi) and go myself. The taxi's are usually like $7.00 to get there so no big deal. Once you get there you can tour the grounds yourself. You obviously won't get to go to the beach if that was what you were interested in but your post seemed more like you wanted to see "The Dig" and other resort areas.
Discover Atlantis:
Immerse yourself in the legend of Atlantis during this exciting excursion. After a 35-minute historical harbor cruise to Paradise Island Ferry Terminal across from Atlantis, you'll be escorted to the resort to begin a guided journey through the attraction, Discover Atlantis. Home to more than 120,000 fish representing 150 species, this attraction re-creates the lost city of Atlantis while providing a fascinating look at life in the ocean's depths. Return ferry transportation is included and available until 5:30pm. After this time, you will need to take a taxi (additional cost) back to the ship before departure.
NOTE: This excursion involves extensive walking. Please wear comfortable shoes.
Adult Price: $33 (ages 10 and above)
Child Price: $23 (ages 3-9)
Departure Times: 11:00 am, 1:00 pm
Atlantis Beach Day:
There's something for everyone on this full-day adventure that begins with a 35-minute historical harbor cruise to the Paradise Island Ferry Terminal across from Atlantis. Upon arrival, we'll provide you with a beach chair and towel and escort you to a reserved location on the beach to bask in the sun and surf. Enjoy lunch at the Dive In snack bar (coupon provided), and the day is yours to spend as you like. Enjoy gaming at the casino, shopping at a variety of unique stores or visiting Discover Atlantis, a unique marine habitat that's home to more than 120,000 fish representing 150 species. Return ferry transportation is included and available until 5:30 p.m. After this time, you will need to take a taxi (additional cost) back to the ship.
NOTE: This excursion involves extensive walking. Please wear comfortable shoes. Use of the pools and water slides is not included.
Adult Price: $60 (ages 10 and above)
Child Price: $45 (ages 3-9)
Departure Time: 9:00 am