I googled for some of these..
I found something for black divers, single divers and christian divers. I did not immediately recognize anything for irish, white (or aryan), bi-polar, dyslexic, muslim, married, divorced or widowed divers. Admittedly, I did not look hard.
I think the context of many people's lack of understanding is dive clubs which identify themselves based on sexual orientation, right?
Personally, I don't care one way or another if there is such a club or whatever. I also don't care about whether the club wants to have an event that invites its members only or invites only a specific type of person.
I wasn't actually talking about dive clubs related to specific minorities. I was definitely getting a bit askew of the original point of this thread so if that was indeed your point, it's been taken. As for "gay" dive clubs I've not seen one yet that required you to state your sexuality anywhere on a membership application. Every "gay" club or place I've ever been associated with was "straight friendly" as long as you didn't have a beef with gay people being gay. The few dive clubs I've talked with don't even focus on the gay so much except in name only. It's not like it's a topic of conversation at club meetings and such, as far as I can tell.