The water is heated in February, so you should be fine. When we were there January 1st, the lazy river water was like a bath tub!

Just bear in mind that the water where the dolphin swims are held is much cooler than the other pools (I believe the trainer told us it was kept at 77 degrees) as dolphins do not like it much warmer. In fact, she said they didn't even "like" it that warm, but to keep it cooler would mean us people wouldn't want to join in on the swim.
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