Somehow we got from "circle hooks for halibut" to "circle hooks for lingcod." I have never considered using circle hooks for lings because one of the first things you want to do is put alot of pressure on them to get them out of the rocks so they don't break you off. If your waiting for a circle hook to set itself that would be a problem. Just use a J-hook with the barbs piched like for salmon and don't give them slack. Same thing for rockfish. Circle hooks have been proven to be effective for halibut, but only when fishing bait.