Topic: Fixing spider cracks in gelcoat
It's generally called crazing and quite common in boats prior to the 1980s. There isn't much that you can do about it. Some have ground them out with a Dremel tool and filled them with polyester and gelcoat only to have them return. It's the nature of the beast where relatively brittle gelcoat lays over a flexible FRP base. The ones around stanchion bases could be due to flexing and may be helped by adding strong backing plates. Keeping the areas waxed is the common way of keeping moisture out.