When you were in Texas, did you ever have a chance to drink Mexican aguas frescas? They’re basically fruit juice, water, and sugar. Delicious! I make agua de sandia at home: mostly watermelon juice, with juice from 3 or 4 small limes, a bit of sugar, & chia seeds.

I don’t know of any analogue in cultures outside of the Americas, though it stands to reason that there might be similar drinks elsewhere, especially in tropical regions.