Hi Peter,
I have been fishing the wall for many years on and off and unfortunately have never managed to land a jack from the wall. But I have had the pleasure of being with blokes out on the North wall that have landed a few and more. We (they) have seemed to do better on a turn of a high tide using poddies. My mate landed 4 in 20 minutes on day just past the drop off tending just onto the sand area. We (they) have also landed them with bait drifting down the wall on a run out tide and done better with a lumi for weight on the line. I just sit there and always wonder what im doing wrong. One day it will happen. Good Luck!