Pictures, show pictures!
I was concerned that even a thin batt would make it too thick but I'm also concerned that no batting will just make it flat, and I know I don't need/want to quilt it heavily.
I just got done making the sail boats themselves. Think I will go with the fleece since (a) I already bought it and (b) I designed the quilt to fit the width of the fleece. So I still will put on some more "sky" (top and sides) and each block will have a different ocean print (bottom). Then I have some "foot prints in the sand" fabric to use for sashing. If I go with the traditional back, it will be too wide for one width of fabric (unless I don't add the sky).