The thermocline on Rough starts from 20-25 ft deep depending on how far upriver you go. I was holding the boat in 35-40ft and WAY off of the bank and graphing fish everywhere from 15-30ft with the biggest numbers being around 20ft. unless you're fishing really light line 1/4oz weight will pretty hard to feel at that depth. I was using a 3/4oz on c-rig and 3/4oz football head and that seemed about right for me anyway. I'm really still learning the deep fishing so I'm not an expert by any means but Kyle is giving you some good advice with the spoonplugging book. I got it last week and it's some great reading.