"PIPAS"

That's pronounced "pee-pas" and you can hear vendors calling it out all over town on the weekends, from the streets to the beach. The vendors sell the coconut juice in a plastic bag, sometimes chilled. Some put a straw in the bag and others just make a hole in the bag's corner and drink from the bag. It's not uncommon to see discarded coconuts with holes in them just about anywhere here.
The surfers tell me that it is not like water and can cause dehydration if that's all they drink. The girls tell me that it is great for their complexion and digestion.

If you've never tried it, chill it first. It's great and there's plenty of them.