Huh. I never really thought about a sexual-orientation based scuba club. On those few occasions when I've needed an insta-buddy, I've not thought it relevant to wonder what the potential dive-buddy's habits in the bedroom involve.
I'm sure there are a few divers out there that are so biased against the GLBT community, that they would not want to be on the same boat as a gay person, but my experience so far has been, we're divers, heading out to go diving. So long as you know what you're doing on the dive, I really don't need to know whether you're bumping fuglies with your same gender, the opposite gender, or any mix of both.
I figure the only reason I need to concern myself with anyone else's sexual orientation, is if I plan on getting into a relationship with them. Since I've been in a committed relationship with the same person for 31 years, and fully plan on keeping it going for the rest of our lives, then the only person whose sexual preferences I need to worry about are hers. Beyond that, I think we should treat other people as people, regardless of whether they're straight, gay, male, female, our ethnicity or another ethnicity, etc.
Of course, I've been called a radical before, too...