Not being able to breathe is a horrible condition.
My daughter is a swimmer. She did real good with it all through growing up and was on the High School team. Now, she teaches little kids how to start swimming, I don't know how she does it, but she is very good at it.
I love swimming. I can do the long slow breathing most of the time. A couple times in my life I could not swim and then I knew things were very bad!