Place the chopped watermelon flesh into the blender.
Add lime juice to the blender if desired for a subtle citrus note.
Secure the lid on the blender and blend on high speed until the watermelon is completely puréed and smooth, about 30-45 seconds. Observe a consistently vibrant, bright red mixture with no chunks.
Pour the blended mixture through a fine sieve or strainer into a large bowl. Use a spatula or spoon to gently press and extract the juice, leaving behind pulp and seeds.
Transfer the strained juice into glasses. Optionally, serve immediately over ice for extra refreshment. The juice should look clear, bright red, and slightly pulsing with freshness.
