How to catch big flathead
THERE aren’t too many serious estuary lure fishermen who don’t dream about catching big flathead. Along with large mulloway, big “crocs” (flatties which are 80cm and larger) are one of the most majestic creatures any eastern coast estuary angler is likely to tangle with. They’re just so big and prehistoric when they emerge from the depths under the boat … and they also look pretty cool swimming away when released. I wouldn’t describe the fight as high voltage, furious or extreme but big flathead do pull hard and have enough weight behind them to demand respect.
To successfully target big flathead you need to understand how they live, feed and survive. The dusky flathead (Platycephalus fuscus) is very common in Australian estuary systems and can be found from Cairns in Queensland right around to SA. They’re a bottom dwelling species and are normally found living on mud, sand and seagrass substrates. Dusky flathead eat small fish and a variety of invertebrates including prawns, crabs and squid. They’re essentially ambush predators which lie and wait (often partly buried) before pouncing on passing prey. I’ve seen them cough up small bream, whiting, tailor, tiny whitebait and prawns at various times.
Spawning appears to occur in the lower reaches of estuaries, typically during summer, which may surprise many readers. The common misconception is that flathead breed during spring and seem to shut down and go into hibernation in the colder months. This is far from the truth. The reason flathead catches drop in winter is because anglers stop chasing them and instead target other species such as bream and mulloway.
Flathead do not migrate, other than to chase a food source or breed in late spring and early summer. They are still there in winter and can be caught on lures.
Dusky flathead grow quite quickly, reaching 40cm total length after three years. They mature at around 30cm (males) and 55cm (females). They are reported to reach 130cm in length, and about 10kg in weight, but the majority of fish caught are 40 to 60cm in length and 0.5 to 1.5 kg. The oldest fish in a recent NSW study was aged at 16 years, but the majority of fish in recreational catches are aged two to five years. This means an 80 or 90cm fish would be around 10 or 12 years old.
You may see a few flathead hanging around flats in water that’s one or two metres deep but I have never seen a big fish expose itself on the flats in daylight hours. The flats are a valuable food source with mullet, whiting, bream, prawns and crabs available but big flathead will hunt these areas on high tide and in the dark when they are much less vulnerable. They will also sit and wait for mullet and whiting to get off a flat as the tide drops, so spend time fishing the deep edges and drop offs around flats.
I’ve never caught a big flathead in water less than three metres deep. In my opinion the big girls just don’t seem to feed or live in shallow areas. Most of the big fish I’ve caught over the years have come from water that’s 5–8m deep.
I’ve seen some big flathead caught over the years on various techniques and many different lures. They seem to be a species that turns up on the most unexpected and unorthodox lures and techniques. I’ve caught some thumpers while tossing soft plastics and hard-bodies at mulloway and I’ve been blown away several times while chasing bream with ultra light tackle and plastics or blades.
The trick to catching big flathead is to target them with the right tackle and lures and avoid them being a by-catch. Fish the right water with the correct technique and appropriate tackle and you’ll be surprised at how many big lizards you catch.
My “go to” technique for big lizards isn’t anything special. I fish soft plastics and use a technique that most anglers refer to as “whipping”. This involves letting the lure sink to the bottom then lifting it up with a quick rod tip lift and slowly retrieving as you drop the rod back down. The quick lift off the bottom gets the flathead’s attention and they usually grab the soft plastic as it sinks back down to the bottom. When done correctly it’s a deadly technique.
I’ve spent a lot of time on the water over the past 12 months refining this technique and it has accounted for more big flathead in that time than I’ve caught in the past 30 years. I was introduced to this technique by a South Coast flathead guru by the name of Dave Johnstone. Dave has probably forgotten more about big flathead on lures than most of us aspire to know and he deserves the credit for helping me on my way to croc heaven many times over. We both fish St Georges Basin on a regular basis and it’s a very rare session where we miss out on a large croc.
To be successful at whipping plastics for flathead you need to cover some water.
It’s no use just sitting in one place blindly casting and working the same water. You need to find the fish and to do this you need to be moving. I use any prevailing breeze to move the boat. A 5-10 knot wind is just about perfect. Use the wind direction to work out a drift that will take you over and through the best water. This means covering the right bottom structure and baitfish activity. I usually mark some bait and bottom activity on the sounder and then line the drift up so I go back over it while casting. If there is no wind early in the morning an electric motor is essential to cover some ground and fish the best water. I use the Minn Kota autopilot to fish a certain line that takes me over the best water. It pays to track your fishing drift on the GPS so you can do the next drift 50m to one side so you’re not fishing the same water again.
If the wind picks up (as it often does in the afternoon) we use a sea anchor to slow the drift down and make sure we cover the best water at the right speed.
Always fish in front of where you are travelling. Use the breeze to cast as far as you can ahead of the drift so you’re fishing new water and fan your casts out to cover as much water as possible. It’s no use whipping that lure back along the same line every cast. Let the lure hit the bottom then wind down and whip it up with an aggressive rod tip lift. Wind back down slowly and let it settle back on the bottom before whipping it back up. Continue until it’s back under the boat. You should be lifting the rod tip and whipping the lure up every five seconds or thereabouts. If there’s a big flathead anywhere in the vicinity you can just about count in her finding that lure and eating it.
From my experience the best water is somewhere between 5-8m deep with a mud and sand bottom. Small patches of weed are good but avoid fishing over thick weed beds because flathead won’t lie in ambush over weed as they can’t bury down it like they can in sand or mud. Any good sounder will detail the bottom and let you know if it’s covered in weed or sand and mud.
Use that same sounder to find baitfish activity down deep in the right water. Like most predators, big flathead will be found near bait and fish activity. This can be bream, small snapper, tailor, whiting or prawns or even other predatory fish feeding near the bottom. Find that bottom activity and you’ll be in with a much better chance of finding a big croc than the guy who fishes barren water with nothing showing.
I started out whipping plastics with my standard flathead on plastics gear of a 6'10" rod and 2500 reel loaded with 10lb braid.
I used two metres of 17lb leader to avoid being worn off if I hooked a big fish. I was soon enlightened by Dave Johnstone that I wasn’t even close to having the right gear. I now use that same Stella 2500 reel but it’s loaded with 6lb braid and has a 2.5m length of 8-10lb Platypus Stealth Leader tied to the end. Loop knotted to the end of the leader is a 1/4 or 3/8 ounce jig head with a 3/0 or 4/0 hook. I like the Gamakatsu Darter 26 jig heads in 3/8 ounce and 3/0 hook. I also use the Fuse Lock Jigheads in the same weight with a 4/0 hook.
In 6-8m of water I find the 3/8 ounce head works fine. I do go down to 1/4 ounce in shallower water around 4-6m deep. The 3/8 ounce head is just right for deeper water as my rod lift is around 3m and it takes 3-4 seconds for the head and plastic to get back down on the bottom. It sits there for a second or two then gets whipped up again. In 4-5m water I lift the plastic up 2m, hence the lighter head and slightly slower sink rate.
I quickly found out that my 6'10" Loomis wasn’t designed for whipping plastics. It was too short and too soft in the tip so it didn’t lift the lure properly and I was continually getting the braid wrapped around the tip. I now use 7'6" rods that are a little heaver in the tip. The two I’m currently using are off-the-rack Shimano sticks, an STP Flats Spin 7102 and an Impact Nano XT 762. Both are Ian Miller designs and excellent soft plastic rods.
Going down to 10lb leader concerned me greatly. Like many estuary lure fishermen, I’ve lost my share of big crocs to worn leaders. The reality is that big flathead don’t head shake like the smaller models. Head shakes are what causes worn leaders and bust offs.
I haven’t even come close to being worn off on 10lb leader yet. About 50 percent of the big crocs you’ll catch whipping plastics are hooked in the top jaw as you whip the lure up. In these cases the leader isn’t even in the fish’s mouth. The other half will be hooked deeper because they’ve had time to inhale the plastic before you whip it again and set the hook. The 10lb leader sits between their teeth and as long as you fight them with steady pressure and don’t get them panicked and head shaking near the boat you won’t have a problem. We fight big flathead nice and softly and never let them break the surface because this is when they panic and head shake.
If you do get a fish hooked down deep take the time to remove the lure gently. I usually find it’s best to roll the fish on its back and remove the lure through the gills with long nosed pliers while holding it with a wet towel. Check your leader and retie the lure on after every fish or pulled hook.
I use several different tails for flathead whipping. I have a definite preference for a certain style of plastic for several reasons.
I only use paddle tails because I believe the tail vibrations are a big advantage. I’ve caught a lot of flathead on grub tails over the years but I now prefer the paddle tails by a long shot. I don’t even carry grub tails in my flathead box these days. I like Black and Gold and also the Root Beer, New Penny or Cola colours, which are various shades of brown.
I also find that green Motor Oil colour by Z-Man to be quite productive. Find some 3-4 inch paddle tails in the above colours and you’ll catch big flathead using this technique. Don’t be afraid to go down to two-inch tails either. I recently caught a 75mm flathead that coughed up a heap of 40mm whitebait, so don’t think they only eat big fish.
Go and buy a big landing net. That tennis racquet sized thing you use for bream will be as useful as itching powder in a wet suit. Get the big, mega barra sized net and in a wide mesh or rubber netting that is fish friendly and doesn’t remove the slime off every croc you net. Go for a handle about 1.5m long that gives you some reach and learn how to swim a big lizard into it head first. You’re going to need that big net this coming spring and summer.
I like a feed of fresh flathead fillets as much as anyone and am certainly not averse to taking a couple of 50cm fish home for a feed. However, I’m dead against any fish bigger than 70cm being killed or harmed in any way. A 70cm fish is probably 6-8 years old, female and in prime breeding condition. NSW Fisheries regulations currently allow you to keep one fish over 70cm but I’d urge all anglers to release any fish close to or over 70cm. By all means get a few photos but support it properly and don’t put your hands in its gills unless you have to remove the lure. Then get a shot or some video of it swimming away. You’ll cherish that memory much more than the pretty average feed that a big fish offers.