The manual is a part of every
OpenCPN installation.
Find the blue button with a "?" on, in the Toolbar, normally at the top of the
screen. Then go to the "Help" tab.
The manual will now open in your browser.
So there is never any need to download the
documentation, unless you are beta testing, and want a local copy of the latest version.
All kind of versions of the documentations are available on the
Download OpenCPN | Official OpenCPN Homepage.
The "Live Snapshot" will be a copy of the present wiki, including all available updates.
Thomas