Out of air with half-full tanks
An article in a recent edition of DAN’s Alert Diver magazine warns of the perils of diving with an isolator valve you only think is open (link below). While your SPG may be telling you that you have phenomenal gas consumption, the reality is that you are sucking the right side of your doubles dry and may soon run out of air without warning. This story hit close to home for me, as I’ve witnessed this same situation twice…and experienced it once.