Thanks for the conversion! I know this may sound silly, but most Yank boaters, can actually not only convert liters to gallons, we can also convert meters to miles. (note: spelling - we also spell differently - it's that American - British English thing!)

DO NOT ATTEMPT TO RUN OR BURN THAT FUEL IN ANY 2-STOKE ENGINE - IT WILL RUIN IT! And, I wouldn't even thing about trying to burn that crap through "my" 4-stroke!
You just completed the description of “Phase Separation in an ethanol-blended” gasoline. Once an ethanol gasoline blend is "phase separated" it cannot be corrected, the "fat lady sang" – get rid of it! You must have bought a boat from a Yank who didn't/doesn’t have a clue or know much about ethanol gasoline?
“Phase Separation” should really be called phase separation “due to water”, as water in the gasoline is the only way it can happen (how it got there in three years, is probably from condensation, but most of the time it happens with water getting directly in the fuel). While you finding water phase separation is and can be a significant problem in ethanol-blended gasoline fuels, contamination by small amounts of water does not lead to phase separation in the fuel. The fraction of water required to induce phase separation is higher in ethanol. However, now that it has happened that water creating the separation is also creating the corrosion of the aluminum tank (your aluminum flakes) – You need to check all metal that has come into contact with that fuel (e.g. fuel gage, pickup tube, etc)!
NOW THAT YOU RAN IT… you might want to go ahead check ALL your rubber, lines, gaskets, and filters – mostly condition (inside) and insure the aren’t clogged – that will clog anything! FYI… if the fuel system is pre-1985, save yourself a lot of trouble and go ahead and replace anything and everything to do with it, as that system (and maybe even engine) was not designed for any ethanol use; that has to do with the older use of exposed magnesium and aluminum metals and natural rubber and cork gaskets, which are susceptible to ethanol (alcohol), induced damage and that does very.
Ethanol is not a bad thing, but DO NOT MIX with any (MTBE) or other oxygenated gasoline – you “really” won’t like the results! And another FYI, MTBE – is worse for you and the environment, you end up with that **** in your drinking water!
If you think it can be treated like regular non-oxygenated gasoline, you will soon find yourself with a tank full of some bad looking ****; and welcome to the land/world of dealing with: corrosion of aluminum tanks (your flakes), build-up of carbon deposits (gunk), and fuel destabilization.
Just for TheBigGuy: it was probably more coincidental that a good problem free TEN YEAR OLD motor developed fuel leaks shortly after switching to ethanol fuels. Not saying ethanol won't help speed up the process of a weak gasket from starting to leak - as ethanol is "alcohol", which is an excellent cleaner!
P.S. I would try donating it to DFO over the Parliament building - they wouldn't even realize it was polluted!