We just got off our 4-night Dream and did Atlantis on our own. I booked the day pass directly through Atlantis since it was slightly cheaper than the comfort suites for us (1A and 2C), and being a first-timer I was nervous about all the unknowns and wanted as few steps as possible. It was very easy. Get off the ship and walk to the taxi stand. Tell them you are going to Atlantis and they will direct you to a taxi (they are all smal vans so you will be with other people). $4/person flat rate. When you arrive at Atlantis, check in at the aquaventure desk and exchange your printed confirmation of your booking for your wristband. From there you walk through the hotel and casino until you arrive at the aquaventure area outside. I would suggest doing some pre-planning with a map as the area is very large and it took us some time to find our bearings. Bring watershoes or flip flops - the concrete walkways are very hot. Towels are provided. The resort is cashless so you will need a credit card to purchase anything. Lockers were available but I did not get one - just left our bag under our lounger - our stuff was fine. When you are ready to leave, walk back through to the front of the hotel and tell them you want a taxi to the port - again they will put you in a van - $4 per person. All in all it was a great day, my kids loved it, and I would do it again.