Good places to look are oil rig platforms, buoys, anchored shrimp boats and even floating debris. The fish also are extremely curious. When approaching a shady area, be quiet and watch. Often times, one or more ling will appear and check you out. In addition to being an incredibly strong fighter, the ling is also very tasty.
Red fish are exceptionally hard fighters, too.
Just ask my wife. Like the ling, the bull red was relating to the shady side of an oil rig. But we never would have known it had it not been for the two rig workers standing on the edge of the platform some 70 feet above the boat. From their vantage point, the workers could actually see activity several feet beneath the surface and they directed us to the area where the fish were. Of course, it is entirely possible the fish the rig workers saw were not red fish at all.