Corey,
I have a single 450 gal fuel tank. It looks like there is a sensor mounted on the top of the tank, see picture.
What baffles me is that I have 2 Smartcraft gauges on the flybridge and 2 at the lower helm station, 4 total. However, only one, (lower helm, port side) gauge is still displaying the triangular, red alarm symbol in the upper left side of the screen. The other 3 gauges all shows the green OK symbol.
Thanks, Scott