Wash skin of watermelon in cool water and a splash of vinegar.
Slice a small portion off the bottom of the watermelon so it sits flat on the counter.
Cut the top off, about 2 " down to form your salad bowl.
In a medium bowl, whisk olive oil, orange zest and juice, lime zest and juice, mix in mint, and feta cheese. Add salt and pepper to taste. Optional, serve the feta cheese in a little bowl on the side and let people add their own.
Using a small melon baller, scoop out all the watermelon, into a medium bowl, leaving just the watermelon rind. Pour any remaining watermelon juice into the bowl with the dressing. Pour the dressing over the watermelon pieces, and toss to combine all ingredients well.
Place the watermelon salad back into the carved out watermelon bowl, and garnish with mint sprigs. Optional, serve the feta cheese in a little bowl on the side and let people add their own.
Keep covered with plastic wrap in refrigerator until ready to serve.