slipf18 and gljurczyk,
Thank you very much for your replies!
I am trying to determine if the cracks are only in the gelcoat, or extend deeper. The roof is not spongy, but these little cracks are everywhere! I was planning to grind out the cracks and fill. But, with so many cracks, I wonder if I will find them all. But, that is how I will move forward. Grind and fill what I can find, epoxy the roof (which hopefully will protect the cracks I missed) and paint.
Again, many thanks!