There are several experienced fly guides running flats boats out of south chatham and harwich harbors. R. J. Sylvester and Greg Weisel are two I would recomend if sight casting with a fly is what you like. Watch the water temps though - if its too hot the fish will be offshore where the water is colder. Early season flats fish are finicky - you want to be on the spot at dawn.
I do the east of Monomoy deep water thing with spinning rods and 12 - 14 lb test in the rips. I have a website at www. sportfishingcapecod.com if you want to hear more. A good cape tackle store to check out is Goose Hummock at www.goose.com.
Average fish in August is 35 "!!!