It is possible to download each required package to the usb and install all packages to update manually, but it is time consuming.
Better find a way to connect your ubuntu pc to internet
and then disconnect after update.
I assume your boat/plotter is in an area where your phone
can connect to internet?, if so, use your phone
to setup a wireless hotspot and connect your plotter to that hotspot over wifi
and do the upgrade
sudo apt-get update && sudo apt-get upgrade opencpn*
If your plotter does not have wifi
, buy a Raspberry Pi USB WiFi Dongle - it costs less than $10,- plug
in to the plotter, connect to the mobile hotspot and run the command above
Originally Posted by Bob Brunius
I have a Ubuntu OpenCPN installation
on my boat
that has no connection to the internet. How do I upgrade my OpenCPN using a USB drive?