Teaching Adapted Aquatics, which includes swimming and water safety instruction for educational and leisure purposes for people with disabilities (Lepore, Gayle & Stevens, 1998), has always been an excellent way to improve motor fitness, physical fitness, social skills, and self-confidence for both people with and without disabilities. See the entire videoclip at http://www.ncpad.org/273/1730/Teaching~Adapted~Aquatics.
Also, see NCPAD's aquatic therapy factsheet at http://www.ncpad.org/12/50/Aquatic~Therapy.