Footloose --- roger roger on the photos from same sail...
I have a dacron UV suncover ... which rightly so ... adds +3 to my PHRF here in SWFL. We get a LOT of sun here and just perhaps North may have overkilled it a bit with the weight of that dacron suncover. As originally delivered and even to 1 year later ... air seems to creep in through the dacron and form a bubble. Now as the 3dl sail shrinks a bit and the dacron stretches a bit this continues with various results in various wind conditions.