We did the Sea Lion Interaction at Atlantis on 2/15/10. Loved it, loved it!
We took the water taxi to Paradise Island. I would NOT suggest that unless you want to 1) move on Bahamaian time (slow) and 2) walk a bit. I would suggest getting a taxi to drop you right at Dolphin Cay (as we had been told by the Atlantis staff when we booked).
Got there and they had very nice restrooms, showers and changing facilities. All towels and lockers were provided at no addtional charge. They also gave everyone a drawstring bag with the Dolpin Cay logo on it and free drinks (water, pop and juice) afterwards.
First we got a behind the scenes tour of Dolphin Cay. I would suggest you wear your shoes for this - we didn't and wished we had had them. We got to see the medical facilities, food freezers, holding tanks for the dolphins and sea lions, etc. Then we got into an empty holding tank and they brought in a large male sea lion (300 lbs or so). He was super cute. He did a few tricks. We got to pet him, feed him, hug him and get kissed on the cheek by him. We were a group of 8 - and we were the only ones in our group. So, it was like we got our own private tour. Love it! Everyone enjoyed it. The youngest in our group was 5. She didn't want the kiss from the sea lion, but participated in everything else and loved it all! We would do it again. We could see all the dolpin encounters in action at Dolpin Cay too. The groups were larger, but everyone seemed to like them a lot too.
We could not take our own pictures. And, that was the only thing not included. The photos were expensive. It might have actually been more cost effective to bring someone along that was not participating and pay the "watcher" fee, just for them to be able to get pictures for us. Just an idea for you all....
Hope anyone that does this, has just as great of an experience! Enjoy!