I do see your point, but I disagree with it.
As a "guy with a boat" I don't care what you dive or how hard you dive on board. I do want to know when to declare you overdue, so I ask what your intentions are if its not obvious.
If you tell me that you're going to do a 1 hour runtime deco dive with a single AL80, in 100' of water, I will certainly ask if you wife/girlfriend is cute, whether I can have a picture to see what I think of her, etc.
If you don't "get it" and splash anyway, I'll call the USCG when you are overdue. If you blow up behind the boat and are choking on your own froth, I've got the O2, and I'll do my damndest to keep you alive long enough for the chopper to come get 'ya.
Now I do understand the "not on my watch" thing.
But let's say that I show up for a dive that I intend to do as a deco dive on some commercial boat. Its not horribly deep (130' or so), I have a set of doubles with an appropriate gas in them, I have a bottle of 50% for deco, and when queried I show you a log with 40 similar profiles in them, and obviously, I didn't kill myself.
Is this enough, or do you want to see an Adv Nitrox/Deco procedures card?
Indeed, do you want to see any card at all?
Why?
Remember, I didn't ask you to fill the cylinders. Its rather obvious that I did get them filled (or filled them myself!) and they have proper contents tags on them. Its also rather obvious that I have reasonable gear for the dive I'm contemplating; you note my single-piece harness, backplate, Abyss wing, high-quality regs complete with long hose, a can light and two backups, all nicely arranged. My drysuit is in a bag along with its underwear. All I want is transportation, and I can present evidence that I'm rather unlikely to be dying on your watch - far better evidence, in fact, than a guy with a newly-minuted deco card who might have
no dives that weren't under instructor supervision! I've got 40, and
none of them were supervised, total dive counts in the three digit range, and a lot of them (indeed, nearly all) are well beyond "OW" limits (deeper than 60'.) I didn't bend or kill myself doing any of them.
Now if you want to make cracks about divvying up my gear as I get on board, or about my girlfriend, heh, have at it. I might make a few in reply myself
But what does a card prove to you?