We just returned from our cruise over Halloween and I bought a day pass for the Rainforest room. I called earlier in the week and they said I didn't need a reservation and I could come anytime. I used it on Thursday the day we were at sea again. It was fabulous. I snuck away three times during the day and there were never too many people there, but I was alone from about 4:30-5:30. As for the hot tubs, I thought they were never crowded compared to the kiddie pool! On our cruise, there was never anyone at the pools after the 6:00 dinner. So night time may give you the most privacy.
Rainforest Cafe, best eating place in the World!!!!!!!!!!Just made our Ressies!!nana2tots

