In the last resort, ANYTHING beats drowning. CESA is an option when all other options are gone. It's good to know it's possible, and I assume we all do, because at least my OW course taught it.
Rather than spend time practicing it, however, I'd rather spend time practicing the things that will hopefully keep me from ever needing it, including good diving practices and other emergency procedures. I might do another CESA some day, just for fun, to prove to myself yet again that it DOES work. But if I ever need to do one for real, I need to sit down with myself afterward and do some hard thinking about how I ever got into that situation in the first place.
Rather than spend time practicing it, however, I'd rather spend time practicing the things that will hopefully keep me from ever needing it, including good diving practices and other emergency procedures. I might do another CESA some day, just for fun, to prove to myself yet again that it DOES work. But if I ever need to do one for real, I need to sit down with myself afterward and do some hard thinking about how I ever got into that situation in the first place.