A 30 year diver told me to never trust a tender who won't get wet, and he was dead right
Early on in my career I worked a pipeline job out of Morgan City and an old diver named Ray pulled me aside. He said, never trust a tender who won't get in the water to check your gear before you splash. I blew it off at the time because I was green and figured the tender knew his job. Fast forward about two years and I'm doing a shallow inspection job with a tender who never once got wet, just handed me my hat and gave a thumbs up. About 15 minutes into the dive my bailout valve was stuck and I had to surface on the pony bottle, which is not how you want to end a shift. Turns out the tender had skipped the pre-dive check on that valve because he never got in to look at it properly. Ray's rule has saved my neck more times than I can count since. So what's the one piece of dock wisdom you ignored and later wished you had not?
Ray's rule works because it forces a second set of eyes on gear that you can't see when it's strapped to your back. A tender standing on the deck giving you a thumbs up is just guessing about hoses, valves, and seals he never laid hands on. I've seen guys skip the wet check on bailout bottles and regs, and it always comes back around on a dive where you need that gear the most. The real lesson is that shortcuts on the small stuff train you to take shortcuts on the big stuff, and the water doesn't hand out second chances.