You might want to add more weight to keep them down or increase speed and let out more line. At a certain speed your jigs will hit bottom depending on how much line you let out, the more line out the deeper the jig. Decide what speed you want to pull. At that speed when rod tip starts bouncing you know you are hitting bottom. Practice, practice and then practice. try not to get discouraged. You are in productive areas.
Wear your PFD!!!!!
This is the day the Lord hath made, rejoice and be glad in it.
Psalm 118:24