People also used to use constant box breathing in scuba as a way to conserve air. Although it was more a triangle breath, with no pause on the exhale. Turns out

People also used to use constant box breathing in scuba as a way to conserve air. Although it was more a triangle breath, with no pause on the exhale. Turns out, doesn't really work for that. But it can still be a nice tool for calming yourself down.