Phase Separation in E10 fuel
Want to learn more than you might really want to know about ethanol fuel and the dreaded phase separation? Check out this study:
I know this is probably way late for the Northern guys, but remember this for next year! Do whatever it takes to find E0 (non-ethanol blended gas) for storing your boat over the winter months. In brief, the study shows that E10 (10% ethanol fuel mix - which has become the US standard) has an increased chance of phase separation as the temperature decreases. The blue stabil will help, but you're much better off with the E0.
If you can only find E15 or E85 at the gas pump, regardless of the time of year, skip the trip to the lake! This stuff will kill your engine.
It's important to avoid having your fuel separate for another reason: your wallet! If you have to have a tank of bad gas drained (i.e. the fuel separated) most dealers will have to charge you a hazard waste disposal fee that could run $8-$10/gal. Do the math on a 40-50 gal tank and you're talking some significant money.
In addition to using the stabil to help fight off the effects of E10, you should also change out your fuel filters often. This is especially important on low use boats. Sounds counter-intuative, but the E10 trapped in there can separate more easily and turn into the brown goo that clogsup your system.