I visited Yellowstone NP recently (my first time, beautiful country.)
I’m not much of a trout guy, but my buddy and I decided to take a drift boat trip. We were throwing a lot of dry flies, and my friend started using aerial mends (reach casts) to defeat drag. Our guide immediately corrected him, though. He was adamant about not using any aerial mends. He told him to let the line hit the water and then mend.
What’s the problem with aerial mends? Is the other way really better?
maybe too much rocking of the boat could endanger boat riders and may spook fish
Guides have a tendency to lapse into mindless repetitive patterns based what has produced in the past, and get surprisingly huffy whenever a ‘sport’ dares to suggest something different. Have seen this for casts, fly selection, leader configuration, clothing selection, etc.
Unlikely it had to do with spooking fish or boat stability unless your buddy likes to accompany his aerial cast with backflips or similar gymnastics. More likely the guide was concerned that you could not get a sufficient mend for the conditions from just his cast. Fishing from a drift boat is a bit different than wading, and mends have a tendency to be pretty aggressive which the guide usually adjusts for by maneuvering the boat. Not knowing anything about the conditions, that is about the only reason I could think of, other than the possibility that you hired one of those inflexible, conceited, Type A personalities that seem quite prevalent among guides.
I never met a guide that knew more than me LOL…
all kidding aside most of the guides I have spoke with are good fellows willing to share their knowledge and
IMHO very fortunate to work in the great outdoors and know it…
I think they get bothered sometimes with Know it alls by no means am I implying that this be your case… just the opposite as I have no idea…
But, Did you ask why…? He or She likely had a reason may not of been a good one but I bet there was one.
Would be nice to know maybe a seasoned guide can chime in… ?
He was very particular where we stood in the boat, but I don’t think that was it.
As my friend said, our guide was a bit “prickly”. In his defense, I think that was partially due to not having a day off in over a month.
As you note, maybe an aerial mend was not aggressive enough.
Definitely not know-it-alls. 
We told him upfront that we were not trout experts and wanted to learn.
We did not ask why. I was in the front of the boat, so all this literally happened “behind my back” without my knowledge. I didn’t find out until after the trip when my friend mentioned it. He just took the guide’s advice and kept fishing.
There are several issues that are unanswered.
To do a proper aerial mend do have to read the water and correct for the unequal flow. This is easier when you are wading and fixed in the water. But you were in a MOVING boat and the same mends that work when you are stationary, for example, and upstream reach from the middle of stream when casting to the bank, may NOT work from a moving boat.
So the first issue is whether your partner was performing the correct aerial mend. You said he was in back and doing a reach cast. If he was casting to the bank, where the flow is slower than the location of the boat, he would need to read the flow of the boat, the flow of the water between the boat and the target, and the flow of the water at the target. Moreover, the guide is rowing upstream AGAINST the flow. So your partner would have to factor that in.
I think this was a learning opportunity. First ask your partner whether his mends were working. If they were not, that is your answer. He could not read the various flows so the guide believed seeing the line on the water would allow him to see how he should mend.
If the reach cast was reducing drag, then ask him whether he was mending the rod TOWARD the guide. In other words, was he interfering or limiting how the guide could row?
Good points Silver
Now you got me curious , next time I go into All seasons in Idaho falls I will see what they might have to say.
Until then I plan to practice my aerial mending, being able to mend effectively is rewarding in catch rates yes ,
but for me it adds to my satisfaction while on the water, I love the art of cast for me catching is a bonus.
Man am I hooked good -
Be safe
Reach casts are very common, in fact necessary when fishing, especially out of a drift boat.
However, rowing and controlling a drift boat is not an easy thing to do. How many of you have operated your power boats and while slowly approaching a dock to tie up several of the other people in the boat move over to the dock side of the boat. This causes the boat to veer off and you have no real control of the boat then. The same thing happens in a drift boat which is why you want to stay in the center line of the boat and not lean way out. I suspect the caster in question may have been moving his body around way too much to try for a wider loop, thus causing the drift boat to veer of course. Just a thought.
Larry —sagefisher—
The boat was flowing downstream, but I understand your point.
If I remember correctly, my friend performed one reach cast. The guide immediately corrected him and told him to do it the other way.
From what I understand, it did not interfere with the guide.
That may be the case. As I said before, the guide was very particular about where he wanted us to stand.