That happened to me. I thought I had a weather window for re varnishing a few weeks back, after a coat of varnish a cold fog settled in, the next day my boat was a milky white mess. Half a can lf expensive epifanes varnish down the drain. It will take more varnish, you can't make it look pretty by sanding now. To fix it, I sanded it all dull and tested the color by putting a dab of penetrol on the dull varnish to see if I was down to the clear. Then I waited for another weather window.