Good for you! I think you'll both have a lot of fun in the water together.
I thought I should let you know - I linked to this post on my blog. I was commenting about the whole concept of over-protective/just-protective-enough. It occured to me just now to wonder how you might take it.
For the record, I don't consider you getting into the water with your son to be over-protective.
But I don't do it myself. I'm too busy enjoying my chance to chat with the other moms, and knitting, and I know my son is a pretty good swimmer. And there's two lifeguards at the pool. I sit at poolside and I keep half an eye on him, but not more than that.
It raises his chances of drowning, yes. But this is one area where I'm comfortable taking that chance. If I wasn't - then I'd be in the pool with him.
I hope Damian has a great time in his swim lessons!