Water therapy (or aquatic therapy) is its own therapy - separate to OT. I think usually done by PTs. It involves a lot of sensory, gross motor, and bilateral coordination, but not fine motor skills.

Here's the link to Dr. Igor Burdenko - http://www.burdenko.com/. He had a partnership with ds's #1 neurofeedback provider. She got all his olympians and professional athletes, while Dr. Burdenko got all her neurofeedback patients. Dr. Burdenko is from the former USSR and developed a national program there, which included water/land exercises. Quite an amazing person!

There isn't a label on the water therapy vest, but this is similar to the one ds used - http://www.hydrofit.com/wet-vest-ii-child/. I think Dr. Burdenko has the vest my ds used under his product tab.

Can2K - those water struggles sound like sensory ones to me! When my son was much younger and in ot/pt/speech etc., we used to rub his face at times with hands, bath scrubbies, soft fuzzy gloves, or other things to desensitize him. I think that helped ds but I still have a ways to go with the nail and hair cutting.