What does the "pool" represent to Sarah?
I would say that the pool represents a force of equality for Sarah. Constantly driving to make peace with her state of being impaired of hearing and the world that does not seem to understand nor care about it, the pool is the one realm where she and everyone else hear the same thing. When she is underwater, it is a realm of not just tranquility but a force of egalitarianism. Hearing and those who are impaired of it can experience the same challenges when underwater. In addition to being a good swimmer, the pool is a sanctuary, a temporary respite from the pain and anger Sarah experiences in the modern setting.