I've done a fair amount of diving in the past, somewhere around 200 cold water dry suit dives. I haven't done any for a few years now. I did about half of my dives off a very nicely operated boat, The Topline, run by a gentleman named Bryce Christie, operating near Sechelt, B.C. on the "Sunshine Coast".
An excellent coffee table book showing this kind of cold water diving is called
"The Emerald Sea: Exploring the Underwater Wilderness of the Pacific Northwest and Alaska", highly recommended.
Bryce operates his boat, he doesn't get in the water, and if you want a "dive master", you'll have to find one yourself. He allows his customers self-sufficiency, you are responsible for yourself. He has never asked me to sign a release. He's allowed me to solo dive from his 40' twin screw boat (sometimes a buddy is more of a hazard than a help), and I've never had a worry about him finding me when the currents have put me out of immediate sight. I've dived the HMCS Chaudiere several times from his boat, and saw the sinking of the HMCS Mackenzie, near Nanaimo as well (dove it that same day). The dives we've done in the Sechelt Rapids at slack were spectacular. Here is his scuba web page (a little out of date):
http://www.sunshinecoasttours.bc.ca/scuba.html
If you know something about diving, spare me the lecture on diving solo. I decided I don't like it, and the difficulty in finding a buddy that is not a hazard, and that I like to travel with, is one of the main reasons I'm not diving these days.
I dive nitrox too. Don't forget that we're not physiologically similar to navy divers, and always keep a safe profile (I'd dive an air profile with a good margin using 32% nitrox, above 110').
Addendum: From his web site, it looks like Bryce isn't operating the Topline anymore. Too bad, it was a nice boat, but Bryce was what really made it work. I'd trust him to drop me in the water anytime, from any boat he was operating. I don't say that lightly, and there are plenty operators I've dove with that I would not say that about; Bryce is pretty much the only one. He's the best.