Speaking of online training, does anyone have suggestions? I did find sidemount.com, which I'm considering. I found a few more videos scattered on YouTube from other instructors, but most of it's rather limited. I think I've picked up the basics enough to try it safely, but obviously don't want to stop there. My primary goals are to (1) side-mount with a backplate setup and (2) have a redundant air-supply.
P.S. There are some other classes I plan to take locally this year, but as mentioned earlier, I cannot find side-mount locally.
Steve Martin's Sidemount.com courses are hands down some of the best courses I have ever taken. WELL worth the money.
Edit: I took the online ones. Easily as good as ANY in-water course I have taken, and better than most of them. He also has in-water if you want. His whole package cost less than the average single course in-water class. Best money on dive training I have ever spent.