I have started taking baby steps hoping to manage pain caused by Ankylosing Spondylitis & Fibromyalgia. I am taking one-on-one swim lessons. The pool is 4 feet deep throughout which takes the fear out of equation. The key is to relax throughout the session. You will feel right when you are in the water that muscles are tightening around neck, back etc if you are not swimming right. This will end up in pain through the spine while you sleep. Watching the breathing is also a key factor. It would be good to do stretches before swimming. Sitting in a sauna after will help loosen the muscles. To get to a point where I can even start swim lessons, I had to bring down my inflammation with prescription strength anti-inflammatory medications. Both Ankylosing Spondylitis and Fibromyalgia kept me in pain for years. I wanted to try moving. That way even if I am in pain due to swim activity, it will have good results in the long run.