Most anglers know that reefs, wrecks and oil rigs hold king mackerel but they also are home to larger predator fish like sharks, barracuda and big amberjack. Try fishing off the edges of the structure or if there are several structures within a half mile or so of each other slow troll live baits or large dead baits from downriggers and flat lines which seems to be the most productive for kingfish weighing 40lbs or more. Menhaden, cigar minnows and cutlassfish (silver eels) seem to be the preferred baits for kings.
Rigging Suggestion:
Use a double hook or stinger live-bait rig. A short, four-foot single-strand copper wire leader is connected to the fishing line with a small barrel swivel. The end of the swivel is fastened to a bait hook (size 2 or so). Connected to the lead hook with a five inch length of wire is a small triple strength treble hook (size 4 or so). The lead hook is barbed through the nostrils of a live bait while the trailing hook is allowed to swing free alongside the bait as it is slow trolled. Not having a stinger hook will allow the king to scream in, rip your bait in half and more times than not get a free meal.