Prepare the watermelon by removing seeds if necessary, then cut into roughly 1-inch chunks using a sharp knife and a cutting board. Measure out approximately 4 cups of watermelon chunks.
Place the watermelon chunks into the blender, add a pinch of salt if desired, then squeeze in the fresh lime juice.
Secure the lid on the blender and blend on high speed until the mixture is completely smooth, about 30-45 seconds. You should see a uniform, bright pink liquid with no chunky pieces.
Pour the blended watermelon mixture into glasses, and serve immediately. For enhanced presentation, garnish with fresh mint leaves if desired.
4 cups watermelon chunks
Optional: add extra ice or refrigerate for 10-15 minutes before serving to chill the drink further for a colder, slushier texture.