Not sure I understand the question, but...
OpenCPN uses the "User Data" directory of Windows to store dynamic data. The exact path varies among Windows versions. You can get a hint by clicking the Toolbar->Help icon. The logfile and .ini file locations are shown there. This is the "User Data" directory.
For static or semi-static data, O uses "Program Files" as default, or whatever has been overridden at install time.
I Portable mode, all these directories are in the "current working directory", i.e. wherever O is executed from.
If the charts
are also in the current
dir, then the entire installation
is "portable", meaning there are no hard-coded drive letter dependencies, and all write activities occur in the current
Does this make it clear?