Hi,
I had an issue that could be related to this with a brand new Tabou 2 months ago (see below). A blister appeared on my second day of sailing, luckily I could swap it for another one in the shop.
Later on I read a couple of threads here discussing this topic, and realised it happens more often than you think (see below).
www.seabreeze.com.au/forums/Windsurfing/General/Small-bubble-on-top-deck-of-board/ www.seabreeze.com.au/forums/Windsurfing/General/Strange-fing-bubbles-on-my-board/ The osmosis theory makes sense. Not sure about your Starboard, but my Tabou and other JP’s have a silkscreened layer with all the artwork, which effectively behaves as a semipermeable membrane through which the moisture manages to go through. If you then happen to put the board in a board-bag inside the car and let it bake on a hot day, the moisture under the layer expands and causes a blister/bubble. After some time, the blister breaks and the detached film gradually comes off leaving a thin crater on the board without the graphics or colour.
I also noticed the other day in the shop that the JP boards now have a sticker warning “Not to put in a board-bag if wet” (I don’t remember the exact wording, but something along those lines).
COROLLARY: Try not put these new generation of boards in the board bag on a hot day