We found a swim school that was a good fit for anxious DS. They offer a pre-level course that helps kids get comfortable in the water. The first two lesson, DS didn't do more than dip his toe in the water. But he stayed there with the class, and interacted with the other kids and the teacher who made it seem like no big deal. Eventually, he got in the water and little by little mastered the skills he needed.
Interestingly, this school has teachers who are specially trained to work with developmentally disabled kids (whose lessons are integrated into the pool with everyone else.) So I think they are very patient and tolerant of differences and quirky kids
