well, chinook are just plain tough, even when you find them in the right places and circumstances. i just spent a week in the queen charlottes with nothing to show for it on flies even though cut-plug success was pretty much in the top 30 feet of the water column. the other problem in washington is the closures of prime water, such as the inside waters of neah bay (sekiu will have a short king season starting next week, but i'll probably just plain avoid the mob-scene that will be). i'm hoping to get some time to check out the offshore banks off ucluelet and bamfield within the next month plus work some of the offshore shoreline at neah bay but who knows how successful that will be. my personal catches to date have been small blackmouth... which i can hardly translate into success with the big boys.
the book by jim crawford on pacific salmon on flies has some tips and ideas... but his flies imo are mostly imitating cut-plugs and jigs... and i personally want to imitate what they are feeding on and not what others are catching them on (call me stubborn). plenty of people have spent time chasing kings in the salt with flies, and nobody is just killing them to my knowledge. if only they were as aggresive as coho <G>.
the problem is that much of the prime water for kings (shallow feeding kings all day) are in places that are kind of isolated. i think it takes quite a bit of time to figure out any fishery (especially one as tough as chinook) and getting the time in these destinations can be pretty cost prohibitive. i know that in my week up in the charlottes i learned a lot, and if i get a chance to return i will have a better idea about flies, techniques and places to fish.
and nwflyfisher, don't start trolling flies if you don't have to. trolling has been useful in learning the water where i fish, but i don't do it much at all anymore. casting and retreiving is way more fun (plus is actual flyfishing <G>).