Giant Trevally (called “Ulua” in Hawaiian; “GT” in Australia) have been an obsession of mine since childhood. Growing up in Hawaii they were the ultimate near shore gamefish. They are the largest member of the Jack family and are the kings of the reefs where they live. You see them on bumper stickers a lot down there for whatever reason. However, despite several close encounters, I was not able to finally land one until age 34.
Giant Trevally live in tropical reefs throughout the Pacific and Indian Ocean. They are pure muscle and a very, very tough adversary even on heavy tackle. They typically charge out of the reef, grab your lure, and then charge back in and brick you in the rocks.
I had one trip to the Republic of the Marshall Islands where every single Giant Trevally I hooked broke me off in the rocks. I was only using 50lb braided line and that was not enough to land a single one, even ones that I could see were only in the 10lb range. I never underestimated them after that and do not fish for them with less than 100lb braid.
Giant Trevally top out around 200lbs but fish that size are nearly impossible to land on sportfishing tackle because there is almost no way to keep them out of the reef. The hook will bend, the line or rod will snap, or something will give before a fish that size will. Anything over 100lbs is a real trophy.
If you are fishing for these using poppers or stickbaits, you need a very stout spinning or conventional setup capable of making long casts with these heavy lures. I would not go with less than 100lb braided line and a 200lb monofilament leader (poppers) or 100lb fluorocarbon leader (stickbaits). The only reel I would fish with is a Daiwa Saltiga. I would pair it with a high end rod from Japan made specifically for this type of fishing such as a Smith Komodo Dragon (poppers) or a Carpenter Coral Viper (stickbaits).
If you are fishing with bait from shore as is common in Hawaii most people use a conventional reel with a long rod for casting past the rocks. You need a reel that can hold a lot of line since you can’t chase the fish. I personally have not caught any this way.
Whatever tackle you use, make sure everything is in top condition. If there is any weakness in anything – hooks, split rings, lure, line, knots, rods, etc – you might as well not even both hooking them in the first place because the fight will be over immediately. Hyperwire split rings from Owner are a good choice when you need to use a split ring.
Giant Trevally readily eat baits but are much, much more fun to catch on topwater lures.
Giant Trevally love large poppers such as those made by Heru, Halco, and many other manufacturers. You cast them as far as you can, and then retrieve them with long sweeps of the rod so that the poppers kick up a lot of water. You should vary your retrieve speed to figure out what they like. The strike is often dramatic as they launch out of the water in a shower of spray trying to annihilate your popper. As with all topwater lure fishing, you have to wait until you feel weight on the end of your line before setting the hook as the fish often miss the lure on the first try.
Giant Trevally also love stickbaits such as those made by Heru and Orion. You can use either surface or subsurface stickbaits; my preference is subsurface. With the subsurface stickbaits you can’t see the strike coming, so all of a sudden you just feel a violent yank as the fish tries to pull your arm out of its socket. When fishing over a reef you have to be careful that your expensive stickbait doesn’t sink into the rocks.
No matter how you fish for them, make sure you get a solid hookset. They often grab the lures in their mouths and hold them so tightly that the hooks don’t penetrate and then they just spit the lure out. Set the hook hard multiple times. To increase your chances, replace all treble hooks with heavy single hooks. They almost always grab the lure head first. You can get away with just a single hook suspended from the head although I like to add a hook at the rear to catch other species that might bite.
I never fish for them with bait but I know in Hawaii octopus and eels are popular baits to use from shore.
Where to get the big ones
The Great Barrier Reef and New Caledonia have some big ones that can be caught on poppers and stickbaits. Indonesia has some good GT fishing, as does Fiji and many of the remote Pacific atolls. I have also heard about some good GT fishing in Oman of all places.