Thanks to Thomas and Pavel I got OpenCPN installed. Here's what I went through, offered for the benefit of anyone else who is new to Ubuntu and anyone interested in reviewing issues that are unclear in the documentation
. I'll be happy to take a stab at editing the manual once I have a better handle on the download and install processes.
I visited https://launchpad.net/~nohal/+archive/opencpn
. The first link I clicked on was "Read about installing". It wasn't very helpful. It ended with "If you're using the most recent version of Ubuntu (or any version from Ubuntu 9.10 onwards), you can add a PPA to your system with a single
line in your terminal. " It wasn't until I revisited the page the next day that I noticed the scroll bar to the right and found the detailed instructions I thought were missing were actually there.
Then I clicked the link for "Technical details about this PPA" where I found a button to "Choose your Ubuntu version". That confirmed for me that I wanted the package labeled "precise". Someone with more Ubuntu experience probably would have known that was the correct name for version 12.04, but I didn't. I selected that version and tried to run "deb Index of /nohal/opencpn/ubuntu
precise main" [the forum software edited the link so that isn't really what I typed] in Terminal. No luck. "No command 'deb' found."
Well, I thought, I'll just download the file and see what happens. At the bottom of the page was an "Overview of published packages" which included opencpn with a version for 3.3.1328-0~precise1. I clicked on it. Nothing happened. Then I noticed another link, "View package details". The same items showed up in the list but expansion links had been added. I clicked on the one for "opencpn – 3.3.1328-0~precise1" and publishing details, change log, available diffs, builds, built packages, and--most important--package files appeared. I clicked on "opencpn_3.3.1328-0~precise1_amd64.deb" and started downloading it.
When the download was complete I double-clicked the file in my Downloads directory. Ubuntu Software Center opened and eventually presented me with a page for OpenCPN that had an "Install" button. I clicked that. Pretty soon I saw a progress bar and eventually it said "Installed".
OpenCPN appeared in the launcher and when I clicked on it everything looked familiar. It has been a long time since I had to point OpenCPN to my charts
directory but I still remembered how to do it. I forced a full database rebuild
and the program ground away for quite a while. The only complaint I have about what happened next is it put me in the middle of the Bering Sea. I was afraid of being crushed in the ice like Shackleton's Endurance! I managed to get my position moved back to Florida--which is plenty cold enough these days--and everything looks a lot like it does on my Windows installations.