I got thrown off after 200 proof. 194 is as good as it gets through distilling. Running a sophisticated dehydration system 200 is possible but once exposed even for a short time to our atmosphere is over and done. Just sitting doing nothing in a fuel holding tank waiting to be pumped into your vehicle/boat it is constantly gaining moisture and loosing “proof”.
“Completely fill the tank with E10 fuel to maximize the amount of ethanol in the tank to absorb any water present”
The above is what is so rough on injectors, they can not stand the water that ethanol absorbs and passes through. Straight gas does not mix with water there for not passing it onto the injectors. Granted, we all hope not to have water in our fuel, but it happens. I’d rather stop it at the filter/water separator than pass it through mixed with ethanol.
Bottom line to E10 in boats… Use non-blended fuel if possible. Especially if you are a monthly boater. Weekly boating and fuel replacement I’d use E10, but as I am lucky to go once a month I re-fuel with non-blended fuel.