For those who may not know: Here's how you figure how many
Gallons Per Hour (GPH) you are using....which is the Only credible way to measure fuel use in a boat. MPG is for
Road Vehicles. Cars have NO SLIP passing over the road. Boats have SLIP because propellers are not as efficient as rubber on the road.
The only instrument you need on the boat is an engine "Hour Meter"....and a $6 calculator.
Fill up the tank and NOTE ...(Write It Down) the reading on your hour meter. Drive the boat for however amount of time you feel like risking running out of gas. How Lucky ARE You Feeling today?

Go to the marina and gas up...FULL TANK.
NOTE how many gallons you Take On to FILL the tank. Get out your little calculator and determine how many hours you have used the boat since you
Last FILLED UP the tank. Say you have used the boat for 10 hours. Now look up at the fuel pump on the dock and see how many gallons you just pumped into the boat. Lets say you pumped 30 Gallons.
So you used 30 gallons....in 10 hours of use. Enter 30 into your calculator and DIVIDE by 10. You will get 3 GPH.
This seems pretty simple and will insult those who already know this but those who don't....... may find it usefull.
So write this formula down... Gallons Pumped to FILL UP.. divided by Hours since the last FILLUP.

NB