Did this a similar install about a month ago. As packaged, the headless install gave me the same issue which you are describing - loss of internet. It only wants to talk to nav system I wanted to be able to access both the remote device (in my case a recycled iPad mini at the helm) and also be able to download charts through a hotspot.
Here's my simple approach. Don't install headless, and use a cheap hotspot box (or a router) as your hub. In my case I have a tmobile hotspot which I have both the Pi4 *and* the iPad attach to (this runs on battery but also charges off a 12v socket...just pulls about 1 amp). Now you have remote control from the both your Pi4 keyboardand the iPad, plus you have internet through the hot spot (note this hotspot keeps devices communicating even if you sail off and have no cell service...slick!). Setting up without using the headless package allows you to switch to another wifi (like marina service when you're stationary and not running the helm as well). To make things sweeter, I have the Pi4 running off my 12 volt socket along with the iPad (using an Anker socket which powers TWO usbs, one C type for the Pi4 and another standard for the iPad). No need for inverters. I also have an Anker battery that will power the Pi4 about 4-5 hours. And on top of that I still have HDMI output for my 32" display in the saloon. I am essentially able to run perpetually with this setup (sans the BIG screen) off off my 12v...and have backup battery power for all devices.
This took a little tinkering, mostly in getting my large HDMI display and the iPad set the same (1650 x 1050 resolution seemed ideal). I use VNC as my comm link. Seems to work reliably, but best not to set charts at the very highest detail if you pan around a lot). Hey, I'm only going 7 knots so kinda irrelevant though. I have a gps interfaced and anticipate hooking in a new radar and my old autopilot this summer....still have some tinkering to do, but thus far, I'm very satisfied. Have about $200+ in it including the GPS (a $30 hockey puck sort that grabs 7-9 satellites from INSIDE the cabin of my Bristol).
There are a few weird tricks and settings (start up config lines and graphic settings), and setting up a VNC account and downloading the app to a tablet, but I've written a page of config instructions so I can replicate and fix things. I can share.
You can do this!
Helpful?
Here's my simple approach. Don't install headless, and use a cheap hotspot box (or a router) as your hub. In my case I have a tmobile hotspot which I have both the Pi4 *and* the iPad attach to (this runs on battery but also charges off a 12v socket...just pulls about 1 amp). Now you have remote control from the both your Pi4 keyboardand the iPad, plus you have internet through the hot spot (note this hotspot keeps devices communicating even if you sail off and have no cell service...slick!). Setting up without using the headless package allows you to switch to another wifi (like marina service when you're stationary and not running the helm as well). To make things sweeter, I have the Pi4 running off my 12 volt socket along with the iPad (using an Anker socket which powers TWO usbs, one C type for the Pi4 and another standard for the iPad). No need for inverters. I also have an Anker battery that will power the Pi4 about 4-5 hours. And on top of that I still have HDMI output for my 32" display in the saloon. I am essentially able to run perpetually with this setup (sans the BIG screen) off off my 12v...and have backup battery power for all devices.
This took a little tinkering, mostly in getting my large HDMI display and the iPad set the same (1650 x 1050 resolution seemed ideal). I use VNC as my comm link. Seems to work reliably, but best not to set charts at the very highest detail if you pan around a lot). Hey, I'm only going 7 knots so kinda irrelevant though. I have a gps interfaced and anticipate hooking in a new radar and my old autopilot this summer....still have some tinkering to do, but thus far, I'm very satisfied. Have about $200+ in it including the GPS (a $30 hockey puck sort that grabs 7-9 satellites from INSIDE the cabin of my Bristol).
There are a few weird tricks and settings (start up config lines and graphic settings), and setting up a VNC account and downloading the app to a tablet, but I've written a page of config instructions so I can replicate and fix things. I can share.
You can do this!
Helpful?