I'm pretty sure that 99% of marinas sell gas with no alcohol. Marinas know the bad effects of ethanol in boats.

It varies state to state as tot he fuel you get at the pump. Our fuel here is all labeled if it contains ethanol. Most land stations have 87 non ethanol, 89 E10 and 91 non ethanol. Some have 93 E10.

I know in Missouri, that almost all fuel at the pumps is E10 unless they specifically state that they have non ethanol.

I would avoid ethanol fuel if you have fuel injection. It will cause it to vaporlock much easier. Carbed engines are not as much of a problem.