GT Fishing Basics

By Chris Henry

If an adrenalin hit is what you are after when you hit the water, then look no further than the Giant Trevally. These fish are bullies and downright thugs of reef systems and island groups over the top half of the country. They hit surface lures with unrivalled aggression and will expose any weaknesses in your tackle and even your personal fitness. At full maturity, a GT can weigh in excess of 50kg, with common catches around 25-35kg and record captures over 70kg. When targeting fish of this calibre, preparation and planning is of utmost importance. Here are just a few basic tips to get you in with a shot at one of sport fishing’s most prized target species.

Gearing up

There is a fine line between buying a setup that is strong enough to pull in a sunken ship and one that you can actually hang on to without doing a front flip on the hook-up. Try not to get your ambitions mixed up with your ability and buy something that suits your strength and confidence level. For a starting point, I would stick between a PE8 and PE10 setup although I would happily recommend dropping down to PE6 for a beginner or first timer. Once you gain more experience then by all means move up in line class, but I must stress that it is a strenuous exercise when fighting these fish and wouldn’t recommend diving straight into a PE10+ outfit. I run a 20,000 Stella SWC on a PE10 Ocea Plugger and find it to be more than enough stopping power for fish exceeding 40kg. I also recommend using gloves and a gimbal belt, as the leverage on these rods are enough to cause damage to your stomach, leg or (gasp!) groin region.

Leader size will be determined by what line class you choose to run. For a guideline I personally wouldn’t go below 100lb even on the lighter setups and choose to run 200lb on my PE10 setup. Your leader should be long enough so that you have a comfortable length out for casting but yet still have your finger on leader material. The reason for this is that if you are making repeated casts with your finger on the braid it will wear the integrity of the line and may result in a line failure.

Lures and terminals

Large cup faced poppers (between 150 to 250mm) and stickbaits (180-300mm) are the main calling card for this style of fishing. It doesn’t hurt to stock up to give yourself options if the fish are being fussy. GTs are very aggressive when they hit a lure, but on some days, can be fussy. A big mistake a lot of people make is not matching the size lure and terminal tackle to the action of the rod and breaking strain of the line. Take into account the gauge of the hook as to not go too thick so that you cant set the hook. Going too thick will give you trouble when setting the hook, go too light and the fish will turn them inside out.

Knots and rigs

Seeing as you are casting such a heavy and long leader through your guides, the good old uni to uni certainly wont make the cut. FG and PR knots are the most common leader knots for this style of fishing with a few other variations getting around. On the business end of the leader a solid ring to split ring or a swivel to split ring combo via an AG chain knot is the go for quick lure changes. Buying a quality set of split ring pliers is a necessity! Instructions for these knots can be found all over the internet and a simple Google search will give you plenty of variations.

Finding fish

Giant Trevally can be found along the entire stretch of Queensland coast, from the NSW border, all the way north to the Cape York peninsular. Shallow inshore reef systems and island groups are the perfect place to find these large predatory fish. What you are looking for is any structure that rises out of deep water obstructing current flow. Pressure edges, points or bottlenecks where the current is either upwelling or being concentrated around these areas are where these fish will be patrolling. Any form of bait presence in these areas, no matter how subtle should be investigated including bust ups from other species like tuna or mackerel. Often, trevally will feed with and/or on other schools of fish below these schools without even breaking the surface.


Once you have determined an area to start working, it is now time to plan your attack. When positioning your boat, take into account the angle in which you are placing your casts along or into the structure. Almost immediately, once hooked, trevally will run for deeper water. Having your boat positioned on the shallow side of a ledge or casting over a deep drop off would only be setting yourself up for failure.

Trevally have a reputation for being dirty fighters and I feel that may be a common misconception. They aren’t the type of fish that head butt into the reef like a yellowtail kingfish, they actually just like to go deep and swim parallel with the drop off once hooked. Because of their sheer size and power plus the tension in the line, if they swim you past a chunk in the reef or a rock you are toast! Really, take your time and think your approach through, angles are everything! If you feel you have hooked a fish in a bad area or on a bad angle, back the drag off, reposition the boat and then continue on. More often than not, a cool head and smart angling will see you boat more fish over pure brawn and heavy hands.

I can assure you there are only a few things in fishing that are as exciting, painful, exhausting and rewarding as getting your first taste of a landing a GT on topwater. Planning and perseverance is the key so put in your research, do the reconnaissance and when your arms feel like jelly from casting at water all day, do not put that rod down because that next cast could have you connected to the fish of a lifetime! Good luck and tight lines.