Water / Holding tank level monitor system

[seaman-recruit]

So I was looking online at automatic fire suppression systems for the engine compartment and ran across these gadgets (http://www.fireboy-xintex.com/liquid-level-monitors.htm) which look like they might be handy. Has anyone out there installed these (or similar) that can comment on ease of installation and satisfaction with the investment?

[jeffmeans]

Those look pretty cool, I think I'd like to get the 2 tank system and mount the gauge/meter on the starboard side radar arch cover where the stereo speaker also is. Fishing wires forward inside the gunwale to reach the dashboard is impossible on my 2001 model year 2900 SCR. I've already mounted the XM Radio receiver there and also a MinnKota air/water temperature display on that cover plate... what's another gadget?!