Watermelon gazpacho soup

This is something we had at the Health Getaway a few weeks ago. I haven't tried it out yet (the recipe that is, the soup at the Getaway was great!) and am not sure I wrote everything down right.

Ingredients:
2 cucumbers peeled
1 watermelon
some mint
zest of lime
small amount of lime juice (optional)

I think that's all! blend most of the cucumber and watermelon in the blender. save some to chop up and add to the soup.