I was able to complete Derby Dash today and things that helped:
x10 Whispering Stargazer
Weaver Fish Hat + Bismuth Fish Friend
x1 Ghoulfish Delight + 1 Ghoulfish to Throw
x1 Rainbow Lure
x1 Regal Fishy
+300 Fish Skill
Week 1: I spent most of my time catching fish around Isle of Dorn and a few in Ring Deeps / Hollowfall
Week 2: Prioritized Azj Kahet with the whisper fish and getting lucky finding a royal ripple pool (This was my hardest fish due to everyone wanting them as well).
I did not need angler thread or any blue tools. This is completely fine in just greens and knowing which pools to go to.
Good Luck everyone o7
Kansei jya