You may want to try what we were using from the fishing pier at Lavon. I was casting a 1oz trolling weight inline with a very light crappie jig tied 18" behind it. The other guys where throwing a 3 way swivel with a short line to a regular weight and then an 18" to 24" line to a crappie sized jig.
I was able to feel the weight bounce on the rocks and it never got hung up. I had 30lb braid to the weight then 10lb mono to the crappie jig, so when my hook snagged, all I lost was an inexpensive jig head.
This was before they opened up all the gates, but the concept would still work, you may just have to increase the weight.