I am new to sinking brush too and have not had the opportunity to do any thing at all as much as I intended to this year, so , I ain't no expert about sinking brush. But, I do know a few things about Oxbows. If you know where a ditch or creek drains into it, that will be a spring time spot. I would develop brush in water 6' or deeper. You may find a difference in the bottom where the old channel used to run. The difference might be less than a foot deep, but it is still a channel. I would drop some mats every 100 yards or so to drift over in the dead of winter or summer. I don't think you will have any water much deeper than 10' in the whole lake so I don't know if condos would be a good idea; unless you wanted them to stick up out of the water to stink it up for them skiers Look at the article that Jerry Blake wrote about building condos and mats. I think the mats would make a big difference in an oxbow with no cover.
DP
I am a heterosexual male. 2 Chronicles 7:14
"If my people who are called by My name will humble themselves and pray and seek My face and turn from their wicked ways, then I will hear from Heaven and will forgive their sin and heal their land."