Outboard Size??

[tartansailor]

Let's face it, water gets into fuel via moisture condensation in the tank, and short of adding moisture absorbent columns in the fill and vent, there is no stopping it.
So the most effective method I can think of addressing that is to add a scavenger that is soluble in both water and fuel, that also happens to burn.
Butyl Cellosolve. I bought a gallon on line and use sparingly, say 1/4 cup to 6 gallons.
Usual precautions (for any organic compound like gasoline etc,) apply.

Dick

[rtwhitman2]

All: how about the drag associated with an outboard located in an engine well; is it significant under sail? And, will an outboard operate in a well with the hatch closed?

[Kilgore]

I've never sailed without the OB so I can't answer your first question, but there is probably more than a little drag.

Mine runs fine with the hatch down (it has twin cowl vents).