82 gallons or so.
The interpretation of the gauge depends on the angle of the boat. It is quite easy to got from 6 bars with two fisherman aft to two bars when those folk move to the helm.
When there is one bar and it is flashing, you have 20 gallons or less. When you see three bars change to two bars, you have approx 40 gallons or half a tank. Every eight to ten additional gallons or so will add one bar but don't bet your safety on the reading alone. For the record, I have never topped off my tank for winter storage, nor do I run it dry. I try to end up with 30 gallons or so of fuel and add a quart of Stabil to that. I take the boat for a short run to mix things up and than haul it for the winter. I have never had water in the fuel, separator or filter bowl. I do check and replace when needed my fuel filler O-ring. My boat is stored in NYC.
I pretty much know what my consumption is for my type of boating and I know my trip distance from GPS. I compare my rough estimate of fuel burn to the gauge reading as a double check. For the record, I have averaged about 1.8nm per gallon on a SX150 Yami, half tank fuel average load and 2-3 total passengers. This average is based on 6+ years of records.
