How sharp should a filleting knife be? I'm trying to learn to fillet and skin fish, and getting conflicting advice.

Most sources say that the boning/filleting knife should be quite sharp. But when an instructor showed me how to skin a trout fillet, the knife wasn't particularly sharp, and the technique seemed akin to scraping the flesh off the skin in one pass. I've even seen some information on-line by a surgeon who got good results with the "blunt dissection" approach, skinning a fillet with the handle of a table spoon. I haven't bought a boning/filleting knife yet, but in experiments my chef's knife (I know, too thick and stiff) tends to cut right through the skin.

I'm coming to the conclusion that a knife for this purpose should be only moderately sharp. (Part of the problem may be standards-- I hone my own knives, and I don't call a knife sharp unless I can shave the hairs off my wrist with it.) Am I on the right track?
It should be slightly duller than a fresh razor blade.  Skill can make up for lack of sharpness, but if you don't have the skills you'll mash the fish more than slice.  This is why instructors and surgeons can get away with dull knives; they've got years of experience cutting flesh.  

Traditionally, fillet and boning knives are sharpened to a shallower angle than general-use chef knives, to allow a keener edge. The only knife in a cook's arsenal that should be sharper is the slicer, which sees rarer use, and needs to be super-sharp for thin slices.