With a prop I would motor along side the bar and try to read the water as to what looks the deepest....this takes time to learn. Generally if you see small rifles in the water and see the shore of the bar extending towards the rifles...its probably shallow there. Try to find water near the shore of the bar that is slower moving..which naturally will be slower closer to the bar. With bow pointed upstream I would inch my way closer keeping the speed of the boat steady to your intended landing location on the bar. You could trim your prop up as you get closer keeping an eye on the depth sounder. When you see the 4 foot mark be prepared to cut the motor...3 foot even more so as you will soon be dinging your prop. At the 2 foot mark you are within inches of the rocks. As you inch closer it's nice to have an anchor ready to be deployed or a dependable and physically capable person to jump out onto the hopefully 2 feet of water and hold the boat..but this is very dangerous. In the summer it's not so bad as most wear shorts, life jacket, and sandals..but waders is another story. Anchoring in 2 feet of water and ensuring the boat has come to a stop is much safer. The most important is to read the water, inch or way closer to the bar, watch the sounder, trim the motor and prepare for docking. A prop saver is handy to have. Then you can pull your boat onto the bar or keep it anchored in 2 feet of water.