I have spaced on the way to interpert the CM93 region codes on the files. Must be an age thing. I seem to recall
that they start at the south pole and work
north, but I don't remember enough details to decode them. Here is an example of what I am looking at.
I know that breaks down to tell me the lat / long fo the area that chart group covers, but . . . .
Am sure it is very simple so please don't laugh too hard at this.