Actually, this month's Florida Sportsman has an article on the problems of Ethanol, especially for plastic and fiberberglass tanks.
Willy, I believe you went with a new fiberglass tank recently. The article even has a photo of a fiberglass tank removed from a boat which is just trashed by ethanol, totally eaten up.
I actually condition my fuel. I have twin 200 carbi Yamis on my boat, which are bullet proof and seem to be able to handle this crap fuel well. If I had four strokes or high pressure engines, I'd follow Pat's suggestion.
High tides and good fuel!!
Juani