I don't know....I read Howard Hall's "don't get into underwater cinematography" rant on his website as mostly a way to keep people from cutting in on his territory. I found it incredibly negative and mean-spirited at times.
Howard's coming from a completely different era, where good gear was not accessible to folks like you and me. It's the same with the music industry; bands don't get record contracts and become stars under the same set of circumstances as a group like Aerosmith did in the early 70's. That Hall had to sweat and eek it out until he could crack into the world of big-budget movie making means nothing to a guy like me who has no desire to shoot for Hollywood. But regardles, the tools to make a good film or video are in my hands, now. It is a veritable techno-revolution out there. I own several broadcast-quality cameras and several pro editing suites, and I didn't spend 50,000 for it, either. I just think that the essay Howard Hall wrote made him seem like a dinosaur. And a very sour and curmudgeonly one, at that.
He does however, raise some really, really, really, really great points:
1) Go into this industry simply out of a love for the animals you shoot. If you're simply psyched to see your photos come out great, then anything that happens above that will be a very, very sweet icing on the already delicious cake.
2) Excellent scuba skills are essential. No exceptions. Learn composition as you go, but don't even attempt to start learning it until your buoyancy's perfect.
3) Learn about how to create good u/w moving images by watching loads of u/w/ films and docs. Personally, I'd add to that that after watching a bunch of the good ones, look at some crap videos, too. It'll open your eyes in a way you never thought possible (or would have wanted, in some cases).
4) Don't bury yourself in insurmountable gear debt. More than a few full-time pro u/w filmmakers have told me this, too. It is an indisputable fact that well-shot video from a 3-chip consumer cam is more interesting to watch than hi-def shot in the hands of a baboon. It's all about composing the shot.
There were quite a few other points he made that I think are valid, but I won't waste yor time. The point is that you probably can't make a full-time living doing just u/w video, but I absolutely believe that through several different avenues, you can make some living. Quite frankly, that's what I'm banking on, too. I don't just enjoy shooting u/w, so that helps my situation.
Ron, I think you'r eon the money in terms of seeking multiple avenues for u/w vocationally, and i also emphatically agree with you that this is not something that requires loads of instruction. Maybe a class or to to learn the basics, but after that it's all about doing it and doing it and doing it some more.