Holding your breath when ascending is the number 1 thing every scuba diver is taught not to do. Divers may hold breaths a little longer or breath out a little

Holding your breath when ascending is the number 1 thing every scuba diver is taught not to do. Divers may hold breaths a little longer or breath out a little earlier to make subtle changes to their buoyancy when swimming horizontally. But this is definitely now how you are trained to ascend or descend.