I would add Taylors Falls, Deep hole back in Close slough, Below closing dam at Blast island. These holes and the ones listed above are the deepest in that stretch of river. 25′ or deeper. Under normal water conditions I would consider 10′ a deeper spot with main channel running 3 to 5′. Late summer water levels even 3 to 5′ main channel might be wishful thinking.
Currently Im running blind without a depth finder to. Going old school. Doing things like paying attention to how much anchor rope is needed. Poke a rod tip in the water to see if it hits bottom. Paying attention to how long it takes my sinker to hit bottom. Was thinking of just throwing my ice fishing flasher in the boat if needed. That will shoot right through the hull. Haven’t had a need for it yet. With dropping water levels by next weekend Im guessing some folks will be using their boats for depth finders. When you skeg plows the sand bar its shallow. When your bow hits the sand bars first its really shallow.