Ethanol isn't a problem for automobiles because they are closed systems used almost daily. It's an entirely different matter for boats, which often sit unused for months at a time and have vented fuel systems that allow moisture to enter the tanks.
In addition to absorbing water, ethanol also is a solvent. It can soften the interior of rubber hoses, and pieces come loose. Pickup tubes in the fuel tank can become brittle and either break off or flake, again sending along particles that can clog the fuel system.
Trident only sells ethanol free fuel.