mudhole

[wb]

I never trust fuel gauges in a boat.

+1

all good advice on this thread

Except Carl!

[Hotrod]

I found the best way is to keep a log on the boat.   Each time you fill up, mark down the hours on the gauges, the hours since the last time you filled up, and a general description of how you ran in since the last fill up.  After a few fuel ups, you can get an accurate picture of your burn rate.   I never trust fuel gauges in a boat.

I got mine down from that..
3 MPG inshore
2.5 running off fully loaded