You can also find them on sale at Jusco in Kornhill. I saw some kid wetsuits (short sleeved body suits) as well as zip-up jackets and vests in the wetsuit material. Various Disney characters, all selling for around $200 (less for vest/jackets).
Actually I see some of the children in my son's 4yo-5yo swim class wearing them. Although there's only 4 to a class, they do spend a lot of time sitting on the edge of the pool after swimming their turn - as the instructor takes them over one by one. At times they do get a bit cold so I can see why parents might want their kids a bit more insulated (Actually I bought a swim vest for my son too, but he refuses to wear it!)