On Board Water Remote Gauge

I'm planning a rebuild of my truck bed platform, with plans for a permanently mounted water tank in the rear of my truck (behind drawers). im trying to avoid having to climb in the bed (under camper shell) everytime I want to check the water level and was wondering what sort of options every1 is using to remotely monitor the water level in OBW systems
Lets hope fueltank sensor is compatible with water immersion.
In industry we use a variety of sensors. Ultrasonic, laser, capacitive & so on. Most of those need threaded boss into the tank.

Is the tank wall visible and somewhat transparent ?
Now that video is crazy cheap, how about a camera ?
the tank im looking at unfortunately is not transparent
That's how I did mine when I had a Valterra tank:

I even measured filling from empty and added gallon-specific markers.
clever. unfortunately for my build the tank will not be anywhere with line of sight to the tank, so i would need a true remote gauge...
Look at RV parts suppliers. There are various potable water senders available. Only issue is they usually read in quarters with 4 led's instead of like a fuel gauge that's infinitely incremental.

See Level II in my RV has a strip that is put on the outside of the tank and sent to a monitor that reads in percentage.
It is pretty accurate. Also has other tank monitors, like for black and grey tank as well.
that option is very neat! i like that you don't need to drill the tank at all -- downside is the set-up is going to cost me more than the tank, water pump, and electrical to wire everything :unsure: