LeFlaneur:
Great. Just what I need, throw a current into the mix.
Windminstrel, I think the gist is, if you can do it in cold and murky you can do it in clear and warm, but not necessarily the reverse.
Wise divers don't "dive" in quarries. They "train" there.
You seldom see people 'practicing' in most popular vacation dive destinations, they're simply experiencing the dives. (And often poorly, but lets not go there.)
You've got the picture - what you need is more quarry diving, not less. But structured diving - working on specific objectives such as bouyancy, communications, navigation, bouyancy, gas management and dive planning, out of air drills, bouyancy, mask removal and replacement, ascending and descending as a team, bouyancy, and so on. Individual skills and team skills. Many divers don't work on such things on a consistent basis, but good divers do. And the quarry is a good training area in terms of being cold, dark, low vis, and psychologically challenging (as well as being reasonably convenient in terms of logistics). Then you find that you are, indeed, ready to begin doing the offshore wrecks and start building skills in an even more dynamic and challenging environment. But it sure beats heading out there and discovering that you're not ready for it some 17 miles offshore (or further).
Before you look for more classes, simply become more familiar with both the quarries and what you need to train there. Then just dive them as frequently as your schedule will allow. The classes offer structured learning, but if you structure your own training sessions you'll often get just as much out of them when working with an equally focused and committed buddy or a team.
FWIW. YMMV.
Doc