Giant Trevally Fin

[Koro]

I'm trying to get a couple of giant trevally fins to upgrade one of my guns. The last 5 days of diving have been pretty much solely dedicated to finding them. But I'm lucky if I can find more than one on each dive. Is there some trick to this I'm not seeing?

[DFogz]

No trick, just harvest them repeatedly and hope for the best.

[Jacky T]

Have you been checking in the sunken cargo ship area? There's usually one in there, on top of a few wandering around on the main map.

[Myth]

I know this will sound silly, but just in case: Make sure you are fishing the right Trevally type. Not Big-Eye Trevally, nor White Trevally.

Giant Trevally typically lurk around 100m in the Blue Hole Medium Depths and are roughly the same size as Sheepshead fish (or Dave for that matter). It's kind of rectangular (not streamlined), dark grey (upper) - light grey (lower) in appearance. The tail fin is fluke-like.

The fin drop is RNG: You just have to keep fishing it until you get one. I've no idea if the drop chance is better if you kill, tranq or net it..

[Jhaeme]

No difference in the kill method that I've found, but I did exactly as Jacky-T said: the sunken yellow boat at the lower left. There are two inside, and there are several at that level outside, around the Limestone Caves and just above The Depths. I just keep killing, then dropping them as they're heavy. I think they may respawn, too, if you go in/out of the boat, and the Sea People cave on the right side. Good luck. :-)