We swim all the time when we go to Disney. We are from up north, so we take any chance we can to swim. I believe the pools are heated. March will be fine and the pool is a nice break from the craziness of the parks( especially for the grown-ups) . I would suggest the Beach Club resort for a water-park quality pool.

karenandtom - Thanks for the swimming info.

After reading a bit of the Unofficial Guide, I am leaning toward staying at the Polynesian. It sounds like DisneyWorld is going to wear us out and we'll need a nice place to go back to - even during the day - to rest! :-)