Diving the way it was done back in the day. Ran across this on "one of the other social media platforms", so I grabbed both the post and the picture from inside it.
For those interested in old-fashioned hardhat diving there is at least one recreational diving certifying agency offering a recreational (I note that twice because they make it clear that it's *not* a commercial dive cert) standard dress course. I suspect demand for this cert is not particularly heavy, so the courses are infrequently scheduled. There are also, if memory serves, a couple of locations where you can do a one time "try dive". I know the recreational standard dress cert requires a SCUBA or commercial cert or military dive experience - not sure about the various try dive opportunities.
Edited the next morning to add: If you're interested, check out https://www.classicdiving.com/programs/ and https://diveamarkv.com/