Today’s question comes from Jim B., who asks. “How about a greased line swing with a 4 foot Airflo fast sink leader?  Would there be any advantage to this? “

The shortest answer is, “Sure.”

The more complete answer is, “Yes… No… Maybe.”

And my best answer comes in the form of a follow-up question, which is: “What do you want the fly to do?”

When it comes to solving some of fly fishing’s thorniest problems, “What do you want the fly to do?” is about as close as it gets to a universal solution. It’s especially applicable in this case. If you want to fish a shorter tippet and give the fly some depth — you’ll achieve depth on the mends because the sinking leader will act as split shot — then have the fly rise toward the surface as tension is introduced — then yes, you have an advantageous situation.

You could fish a neutrally buoyant fly on a longer leader, and have the fly present somewhere between the film and a greater depth. (If that’s what you want the fly to do.)

If you want the fly to sink just below the film and fish it at a depth of 1 foot, then no, it’s probably not advantageous.

You can see where this is going. There are multiple answers because there are multiple possible situations. Which line? Which leader? Which leader material? Which leader length? Which presentation? You can answer them all by determining what you want the fly to do. Hope that helps!