This is our son's lounge chair. REALLY awesome! We can tilt it just right and use NO straps. Usually he has about 10 straps on his body. We had to import it from England and altogether I think it was about 5K out of pocket. Crazy expensive like all things in special needs world!
Please make sure your child is safe around water. Different children need different levels of support; some of these ideas might not be appropriate for your own child. If your child doesn't need a specialized bath chair, a laundry basket, infant feeding seat, or homemade bath chair might be ok. To keep soap and water out of their eyes, you might try a brimmed cap or googles. And, if your child needs a hair washing, but maybe can't be bathed post op, you might try a basin or tray.