Wiki say
"If you wear this ring when you drown, you will lose the ring. On the other hand, you'll keep your life. Might be a nice trade-off?"
so started to wonder how this rings works, once you are out of stamina you drown, so this ring will prevent you from drowning, then what ? you regain all of your stamina or just stay there and its most likely that you are gonna drown again anyway ?