Yellowtail Kingfish are one of the main target species when spearfishing in New Zealand. I speared my first Kingfish at the Hen and Chicken Islands in NZ when I was 14. I shot it in the gut, it tangled the line all over the place and somehow I managed to land the 10kg Kingi. I was grinning for weeks over that. Since then I have landed a few more and learnt a few things along the way. Here's my take on how to spear a kingfish.
Firstly, Kingfish like areas where there are baitfish in residence and this is often where there is a strong current. A common Kingfish hotspot will be a rock or small island in between two bodies of land where there is a lot of current flowing between them. The up-current side of a rock is where the fish will be as the upwelling of the current distributes food for the baitfish If the current is very strong it is best to have someone in the boat to allow you to do a few drifts past the rock.
Kingfish are a curious fish so they will most likely come in to check you out if they are in their vicinity. I usually do a series of dives to the bottom and mid water depending on where the baitfish are. Kingfish can often be speared from the surface but something I was taught from an early age is to get down to the bottom and you will have far better results. I firmly believe this as often the baitfish are down a little deeper 5m - 20m.
Once down wait there for the Kingfish to come in and check you out but be sure to turn your head away as being curious fish they follow your face. If you see the fish but it is a little too far away, you can try strumming the rubber bands on your speargun to invoke curiosity in the fish and bring it in closer. But be prepared by having your speargun close to the body, turn, then point your gun out – this will avoid spooking the fish when swinging your gun.
Next where you place your shot is very important as Kingfish are incredibly strong fish, a misplaced shot can be torn out with ease. Some people will disagree here but I aim for the head of the fish as it usually results in a stone shot, I find the head far easier to hit than the spine (the other stone shot area). But if the head shot isn't on I go for the area just behind the gills near the spine, but not below this as you will hit the soft gut area.
Once you have placed your shot this is where things can really escalate. If you haven't stoned the fish with a head or spine shot it will bolt off and try to tangle the spearline around the nearest obstacle or it will head straight for the bottom. In New Zealand we mostly use a standard 110-140cm speargun with a float line (30m+) to a float.
Head for the surface maintaining some control on the float line. From the surface you can then play the fish, maintaining moderate pressure on the line without pulling too hard on it, so you don’t tear the spear out. Gain line when you can by using a hand over hand pulling action, but when the fish runs hard allow some line to slip between your hands, simulating a game fishing reel.
Be mindful of the loose line you have been accumulating on the surface, if the current hasn't moved it away from you ensure you swim out of it because you don’t want to be tangled in it if the fish takes off again. As you reach the nylon shooting line, ensure the fish has tired somewhat to allow you to be able to bring it in and grab it, if it’s too fresh it will go off like a bag of cats when you try to grab it.
When you do get close to the spear, grab the end of spear with one hand (furthest from fish) and then put your other hand on the other end of the spear by the fish’s body and push the fish against the spear flopper to keep the fish secure. Remove your hand off the end of the spear (the one furthest from the fish) and grab the fish by the gills. Once you have a firm hold of the gills (you may have to wrap your legs around it if its large) you can then dispatch it with your knife by stabbing it in the brain.
Please remember don’t over do it, the NZ bag limit is 3 per diver at a 75cm minimum. I go by a rule set by a mentor of mine, 1 per day max and 100cm minimum. Only take what you can eat as it can be addictive to want to go after more fish, and larger fish constantly. Don’t get caught into this mentality and just enjoy it.