Where did you read that you shouldn't drink the water? Spain, and the rest of Europe isn't like Mexico or the Caribbean. The European Union has water regulations. I've read that the taste is different, so bottled water may be preferable from a taste standpoint, but it isn't necessary.
DANG!!! And here I was hoping for a little case of dysentary to offset all the stuff I would eat on the ship during the sea days on the way over!!!

