Thanks Sunbeam.
Hi jkidd - I also have the engine interface on mine that tracks fuel flow, fuel used, etc. However, there are downsides to that just like there are downsides to using the fuel tank level senders. Fuel tank level senders aren't precise, and can be inaccurate, but they are a pretty reliable indication of approximately how much fuel you have left.
My boat has two 50 gallon tanks with a fuel selector switch which allows you to draw from one tank at a time. The tanks are aluminum and there is no way to visually confirm fuel level as their might be with a composite tank. With a single main engine monitoring fuel flow, it would be difficult / tedious to track how much fuel was left in each individual tank. Furthermore, I've got a kicker that draws from the main tanks. I think it might have an engine interface I could also hook up. Not sure if it has fuel flow.... I'm not going to bother hooking it up to the network. Using the kicker will make "fuel used" readings inaccurate. There are also plans to hook my generator into the main fuel system, and it certainly won't have an engine interface with fuel flow data.
I still think it's handy to have the fuel flow data from the main engine. I have two independent fuel level figures I can compare to each other for a sanity check, and I will have a pretty high level of confidence about how much fuel I have in each tank with this setup.
Mathia