Thanks for all the suggestions. My life is much busier these days, and I won't personally be around home much to spearhead this effort in person, so I'll have to opt for a slightly less labor intensive option than building a real dock, at least temporarily.
My brother's inlaws gave us a small plastic pontoon boat, so now I'm thinking that next Spring I could just tell my people to float the pontoon boat, maybe have it anchored and/or tied off to make it stable enough to serve as a temporary "dock", and then we could attach a couple floating cages to the deep end of the pontoon. I think we'd tie off the pontoon at the dam, which has the steepest slope and deepest water to hopefully be able to get the cages in at least 6' of water (to give the YP as many depth options as feasible and to try to get 1' or so of water underneath the cage, as Bill suggests).
