Old dive supervisor told me to always hand-check my regs, I skipped it once
He said "trust the gauge but verify with your mouth" and I thought it was overkill. Yesterday at the Port of Oakland my SPG read 200 bar but the reg free-flowed at 10 meters, so now I do the 5 minute pre-dive check every single job. Anyone else have a habit they picked up from an old timer that saved them?