Firstly make sure that your doctor knows that you intend to try hydrotherapy as it should be approached with caution for certain conditions. The temperature of the water can alter blood pressure and, as some Parkinson's medications can cause low blood pressure and possible dizziness, it is important to take care when getting out of the pool. It may be wise to limit the length of each session to around 15 minutes if there are concerns regarding blood pressure.
You should also make sure that your hydrotherapy therapist knows that you have Parkinson’s and do make them aware of any problems you may have with breathing or balance.
Exercises should always be supervised by a trained physiotherapist or qualified teacher who will assess your individual abilities and needs. The exercises can take many different forms and your physiotherapist should design a specific programme for you, to maintain and improve your individual physical abilities. A key part of any session will be warming up and cooling down exercises to avoid the risk of any muscular strain.
Many physiotherapists hold classes in the pools attached to the hydrotherapy unit of a hospital or special centre. These pools are usually comfortably heated and have specialised equipment, such as flotation devices, or attachments that help to increase water resistance, such as those that allow for stationary swimming against a gentle jet of water.
Classes may also be available in public pools but you will need to check that these suit your needs and abilities.