Giant Trevally (Caranx Ignobilis)

The Giant Trevally is a super predator that adapts its hunting styles to its surroundings, often hunting in shoals attacking their prey in a ferocious, frenzy like manner. These fish are truly one of the toughest creatures swimming the seas. In certain areas of the Pacific and Indian Oceans specimens in the 20 -120lbs range frequent the flats, lagoons and coral reefs.

Giant Trevally are extremely versatile predators, being found in a wide variety of marine systems ranging from the shallow flats to deep water pinnacles. They are known to exceed 200lbs in weight and on occasion have ciguatera poisoning.


Giant Trevally hunt in conjunction with the tides so it’s very important to plan your fishing sessions accordingly. When fishing on a high tide, your time is spent concentrating on points, drop-offs or areas with a channel or a break in the outer reef allowing them access to the flats. Walking these crystal clear fringes with good light will often produce numerous sightings, giving you ample time to get ready for a cast. But even in the Seychelles the weather doesn’t always go your way. Firstly, you could be looking straight into the sun or it could be windy, the water murky from the shore-break, all making visibility difficult.

Training your eyes to pick up these fish in time to have a cast is not always easy. View way ahead of where you are walking, as often the fish will pass right under your nose sometimes as close as a meter from the shore. In these conditions it’s not always the shape or movement of your target species that gives its position away. Spending your time scanning the water for sharks or skates is often rewarding, as they are easier to spot and often have following fish.

When a GT is spotted and is within casting range, the fly should be presented away from the fish, leading it in order to give it something to chase. A fly cast right onto a GT will in most cases result in a spooked fish. When fishing baitfish patterns, the fly must be retrieved very fast (faster than you can) to ensure that the fish does not lose interest. When casting crab patterns, the angler must also lead the fish .The crab can be retrieved fast or just left on the bottom for the fish to find. We have had success by using both methods. When striking the fish, it is critical to strike on the line and not with the rod. GT’s have hard mouths and need to be hit hard in order for the hook to penetrate. The fish must be fought with a low rod angle, thus allowing the thicker butt of the rod to do the work. The reel drag should be tightened gradually as soon as the fish starts its run. Changing the rod angles on the fish during the fight can help to throw the fish off balance and assist the angler in landing the fish in a shorter time.

GT’s live in the lagoons as well as out at sea. On the ebb, fish filter off the flats following the edges of the channels until they are in deeper water. As the tide turns they follow the same routes, but as they don’t run the risk of being stranded high and dry, they tend to push onto the flats as soon as their backs are covered. Positioning yourself anywhere along this route will allow you ample shots at these devastating creatures.

When the fish start coming onto the flats with a pushing tide, they are generally looking for baitfish. Therefore you’ll find baitfish patterns like a Flashy Profile, Sea Habit or Tan Clouser in 6/0 or 8/0 to be the most productive. On a full tide and while it’s dropping, fish cruising slowly along rocky ledges and drop-offs are often looking for crabs. They will sometimes refuse a baitfish pattern. Therefore a large crab pattern like the Cosmo Crab or Merkin Crab in 6/0 0r 8/0 works well. From time to time you’ll get a fish that refuses both patterns, and if you get another chance it often pays to change to a popper. We find a 6/0 Sliding Head Popper with mylar or in white works well.


When fishing for all big fish, it pays to keep the fly line on the reel and with modern fly lines, leaders, hooks, reels and rods it is achievable. When fishing a heavy leader you should allow for the fish to take no more than 50 meters of backing on its first run. By keeping the rod low, using side strain and short strokes, you can apply much more pressure and keep closer to the fish. When on a sand flat the only problem you’ll have is the occasional coral bommie, whereas on a series of ledges or an outcrop of some sort, you run the risk of being cut off on sharp rock ledges. If it’s not too deep the best tactic is to follow the fish and get onto its same line so if it decides to change direction and run parallel with the ledge you won’t be cut off.


  • Fly Rod: Quick action 9 foot 12 weight fly rod.
  • Reel & Backing: Saltwater series reel that can hold 300 or more meters of 80lbs braid. A Bimini Twist to Double Surgions should be tied into the braid, following which the fly line and backing should be joined using the loop to loop method.
  • Lines: Weight Forward 12 weight floating line with 50lbs braided loops nail knotted onto the ends.
  • Leaders: We use straight 130 lbs Suffix Zippy as to avoid being cut or bitten off. By using this material we land fish as quickly as possible, plus it prevents the fish from experiencing too much stress.
  • Knots: Fly to leader – Improved Homer Rhode or Perfection Loop; Leader to Braided loop – Perfection Loop. NB mono has a stretch factor and a tendency to slip before seating. When tying your knots make sure you leave a tag and seat them properly with the use of pliers. In saying this ensure you do not stress the knot.
  • Flies: Flashy Profiles, Brush Flies and Poodles tied on Gamakatsu 6/0 8/0 – SC12S (Link to fly patterns and fly tying)
  • Boots: A good quality thick rubber soled boot with ankle support.
  • Gravel guards: A good idea to prevent sand penetrating your boots.
  • Sunglasses: Dark amber or mirror blue grey lenses.
  • Glove: A diving glove is necessary to handle GT’s as they have sharp scutes on their caudles which can seriously damage an anglers hands.

Before leaving on your trip you will be briefed in detail by the FlyCastaway guides as to exactly what fly patterns you are going to need and how you should prepare your tackle. For all our destinations we have compiled a comprehensive tackle list.


Seychelles – CosmoledoProvidence, Astove and Farquhar Atolls Mauritius St Brandons Madagascar