Don1Reed:
You have given me a lot to think about. I never expected the charts to be precise and accurate representations of a spherical earth, but I figured by the 4th generation sim, they would be approximately correct. If I understand you correctly, the SH4 charts are, to use a technical term, FUBAR. Some careful checking is in order.
As a footnote: I read what you wrote in an earlier thread about Sh1.
I had a similar experience. I discovered by accident that the distances were grossly messed up. As I recall the island of Borneo was about half it's RL size.

I ended up tabulating the figures into a table for each patrol zone. I have to admit, that error in the game really bothered me a lot. What is so difficult about making a degree of latitude 60 nm?