Bought some berkley powerbait liver flavor and have been trying for some cats with no luck. Usually around 8-9. I've been trying with a slip sinker, swivel, and about 18 inches off of that with the bait. Haven't even got a bite. Any suggestions and how to get at those cats? How shallow do they get at that time. Been fishing in about 5-10 feet at that point. Would it be better under a bobber?