Originally Posted by Corbo
If it looks like food at a given moment trout will eat it
Happy "surprises" do happen though all the time as there is often no accounting for why trout eat something
Someday you will be dry fly fishing in a river with your line trailing out behind you in the current (and paying no attention), your fly will likely get swept under and be "trolling" down river so to speak and while you light your cigar a big fish will whack your fly even though all fly fishing "wisdom" says it should not happen...
This, this and this...
All are spot on while the first point really explains the other two.
Of course a trout will potentially eat a drowned dry fly if it feels so inclined but I would focus on getting a good drag free drift first above all else. I have literally added shot to dry flies to get down to fish because that is all I had and guess what... they hit. Not ideal but presentation is key. If a dry turns into a wet but still looks like food... bingo!