Don't know if they still issue these, but here's what one looks like

Rick
Hey! I have one of those, too. Somewhere. And I have the next one, as well--for IANTD *Advanced* Deep Air Diver. Received it c. 1996. The training manual has air tables which use the two deco gases EAN32 and EAN80, iirc. I believe the training was for a max depth of 220 fsw.
My first 200 footer was during my certification trip (or shortly thereafter) on the "Daniel J. Morrell" in Lake Huron. Don't remember much about the dive. However, I do remember going all the way to the bottom and, trying for maximum depth, placing my forearm on the rocky bottom of Lake Huron. I was so impaired, though, that I didn't comprehend that the business end of my air-integrated computer (Cochran Nemesis Nitrox II) was up near my tank valve, and that sticking my wrist display unit on the bottom did nothing for me at all! (My instructor surfaced showing a max depth that was a couple of feet deeper than mine. He had lain on his back on the bottom! He was an extremely experienced deep air diver and evidently was not nearly as impaired as the rest of us.)
One of my next 200 footers took place off Isle Royale in Lake Superior. There was a spare prop bolted to the deck of this particular shipwreck. (Sorry, can't recall which one.) We were told ahead of time that we would be asked later about this prop. Although I "studied" the prop at depth, when we surfaced I absolutely could not recall how many blades this spare prop had! Was it three? Or four? Maybe three. No, I'm sure: It was four, damn it!
These are funny anecdotes. I've got a couple of truly scary ones, too, that I won't bore you with.
I no longer attempt these types of cold, dark, freshwater deep air dives. Not since c. 2000. I'm much older now, with young kids.
Safe Diving,
Ronald