Here is the one from SH3 that Nordfront did years ago:
Silent Hunter III Mission Editor User's Guide a pdf file. That is a temporary link, so get it while it's hot! lol - one of these days, we'll get around to adding more to that for SH4 compatibility. Most of it does apply in SH4, other than the "Mission" "Parameters" portion of the app, though it is still basically the same, just broken into separate sections for SH4.
