Busdiver, do you think that just 20 post-cert dives is enough to take on the currents in the St. Clair? I had many dives under my belt before my first St. Clair dive and found the dive very "interesting", meaning it challenged me. Or maybe there is a part of the river that is a little less challenging that you are talking about. IMO, you better have a lot of confidence (experience) in yourself and your equipment to dive the St. Clair, at least near the head waters off Lake Huron.
The river is over 34 miles long. The area you are talking about has the fastest most challenging currents. I agree that it is important that you dive that area with experienced individuals. That is why I put Rick and Kevin's name down as good guides. Rick is a more than capable instructor out of Bruno's Dive Shop and Kevin is an excellent instructor out of Sea-Side. Kevin dives this area on a weekly basis. The river is dangerous because it has to be treated as an overhead environment. You cannot just surface with out fear of getting nailed by a boat. That is why I did not say I would take him on that part of the river. It would be beyond my own skill set to have him just with me. Rick and Kevin would need to talk with him, assess his skill level, and go from there. Just because he only has 20 dives should not exclude him from a great dive site. (Heck he is way past PADI AOW at that point, LOL). He needs to do that dive site with really capable folk (i.e. Kevin or Rick).
Now, where I dive the river it is more mellow. The way the break wall comes out and the river bends, a lot of the current is negated. I would not have a problem having him dive with me there. I have had folks in the river at 10 dives and they have loved it. They just need to be next to me and listen to my briefing before we go in. I am a very safe diver and do not believe in putting people in undue risk.
I hope that answers some questions. Please come dive the river. It is fun, it is challenging, it is different. Dive it with the respect it deserves and dive it with people who know it.
Bus