Big River Dun

A larger mayfly with a lot of buoyancy.
It is tied to fish faster water and still attract large fish.
Tied on a barbless Ahrex in size 12.

Fun fact: One late summer day, a friend and I discovered fish that were on shallower, really fast water and ate mayflies, then this type of fly was the only thing that worked. We caught 19 fish in 3 hours of fishing, with fish up to 2 kg.