Graeme Tolton
Contributor
Bad Idea CO2 is only one of the many reasons not to skip breath. The only time that you should ever have to skip a breath is when you have to buddy breath in case if equipment failure.
The way that I was taught buddy breathing in my OW class was to be slowly, but constantly exhaling while the other diver has the regulator, and to NEVER be holding my breath. I am very conscious about my breathing as I really hate getting a CO2 headache after a dive.