Hello cesare, here are the map of "cap de creus" with all the zones:
In the red and orange/yellow, is not allowed to spearfishing. (thanks to "lapescasubmarina" for the picture)
About the astuarias licence...yep it's valid here!
and the temp of the water, will be about, 16-18íƒÆ’í¢â‚¬Å¡íƒâ€š.- C
if you need something else....here i'm