Heather and I took a Parent/Tot swim class over the summer. The first day, she was just super distracted by all the new things to look at, but she took to it really well.
When we started, of course, she couldn't do anything. By the end of the two-week course, she could kick her legs and scoop her arms while I propelled her around on her tummy.
Heather really liked "swimming" around to retrieve the pool toys. And she loved her instructor, who was super sweet and great with the kids.
Next year, we'll still be in the Parent/Tot class, and we'll work on blowing bubbles! (She had zero interest in doing that this summer.)