Complete Basu's request
Talk to Basu
Walk east from Dave's cabin and accept the request for a Piraiba Catfish.
Prepare a mid-depth dive
Bring enough oxygen, carrying capacity, and a combat mode that can handle a large freshwater fish.
Search 35–75 m
Follow the middle lake depth band and identify the broad-headed Piraiba Catfish.
Return with the catch
Finish the dive safely and speak to Basu to receive the fishing rod.