Not that I'm going to know what it is, but I'm a bit
confused at your "timeline" of events here. Is this
about right?

You pumped 45 gallons of gas into your
boat tank on Saturday.

On the way home you had problems where
you could not go above 3200 RPM without
loosing power.

Now you got this gas sample from your
tank at a point that is AFTER it goes
through your fuel filter.

The gas as it comes out of your boat's
system / fuel filter looks about normal
and "clear" but when it sets for 10 minutes
or so it gets cloudly like this.

??