I have not caught a permit yet... but I had many shots at them last year and this year (over 40).
I flyfish in Florida (Biscayne Bay) and from now until March bonefishing and permit fishing will be hot.
Last year, I tried the Merkin and followed advices given to me by Del Brown through Dan Blanton's Email (the guy was allergic to Emails).
I presented the fly correctly 80% of the time. I had the permit rushed to it and then I was waiting... sometimes more than 1 minute... which seemed to be an eternity.
Anyway, they refused my refusal by ignoring the fly, or I spooked them when trying a little twitch.
Wow they are picky... considering I catch a fair number of bones each year and nearly at least one for each half day of fishing... My main problem is probably the lack of experience with permits.
See, for bones, it took me some times to understand how they move and what is the eating mood of the day... Once you have all figured it out, they are really easy as you tune your presentation, stripping and fly according to their behavior... nothing more.
Now, for permits, this is another story...
The fish is so easy to catch on wrecks that they would eat a popper... In the surf they are easy too... and would eat a streamer... (According to the guys I fish with. most of them are guides).
Now, on the flats, they are not easy... but not spookier than a bonefish. Try to cast to a bonefish 3-4 times without spooking it... For permits, I could present the fly many times... switch flies and the permit would not spook, but would come and look at my offering... So, getting the fly to them is not that tough finally.
The problem is all in the retrieve and to read their behavior.
Here are the ideas:
1- when they are tailing like crazy, they are more easy to catch and presenting a crab dropped at less than a foot will generally do the job... (unfortunately, the flat I fish does not hold tailing permits). The Merkin would do the job, but a permit would not take it if it is not moving. The trick told by a friend (guide) who caught a lot of permits is that once the permit has seen it, you should drag the fly slowly on the bottom by 5" and then stop... wait and do it again.
2- when they are cruising on the edges of the channels, it is better to strip the fly. Bob Branham has his own ideas on this and I witnessed the success of his epoxy fly stripped in the current with a pulsating action. The permit generally takes when the fly reaches the boat. Bob says: "permits are not difficult on fly. The no retrieve thing is total bullsh*t. You cannot immitate a crab with a fly as it has no scent... You need to move the fly to make it alive and fool a permit. Permits are a little bit more difficult on fly than bones, but not much. The difficulty is to spot them in great number. They are a more rare than bones that is it. They are just jacks and by stripping the fly, you will wake up this jack instinct. They hit hard you know..."
This is another sentence suggested by a guide: Del (Brown) had more money than anyone to go fishing. He fished with the best guides more than 100 days a year. He had everything he wanted to facilitate his task and get a permit on fly. The merkin is a good crab immitation but with no retrieve the permit will not likely eat it. Del's method is good if you have many opportunities a day." This guide has caught lots of permit on his permit rat fly... with lots of 4 per tide...
Just some ideas about permit fishing and from the information I got from the Internet and friends. They are just fish. There is a learning curve with permits.