Cut watermelon in half. Using a large spoon, scoop out and reserve the pink flesh. Discard rind. Add black salt.

Process the watermelon and lime juice in a blender (in batches if necessary) until smooth and frothy, about 30 seconds. Add water.

Pour the mixture through a fine-mesh strainer into a pitcher, pressing with a spoon to release juices. Discard solids. Pour the juice into 4 ice-filled glasses.

Enjoy