[Geekie1]

Boater. Put a clear glass jar under your bilge drain. (With the boat out of the water, plug removed.) If you have a tank leak, you will see the gas in the jar along with the collected bilge water. That is how I found out that I definitely had a leak. All of the hoses, fill, vent, fuel line, and fuel level sensor are above the top level of the tank and can be checked for leaks somewhat easily. Fuel tank leaks in an aluminum tank are usually caused by corrosion from water in the tank and in most cases are leaks in the lowest level of the tank because that is where water accumulates. Sometimes leaks are caused by abrasion but corrosion in a 20 year old tank is the most likely cause. Just my $.02!!