Use the vegetable peeler to strip the green outer layer from the watermelon rind, then thinly slice the white part with a mandoline slicer set to 1/8-inch thickness. Do the same for the pineapple, slicing into thin, uniform pieces. Place all sliced fruit into a large mixing bowl.
In a small bowl, whisk together lime juice, honey, and salt until well combined. Pour the dressing over the sliced fruit in the mixing bowl and gently toss to evenly coat.
Transfer the salad to a serving platter or individual bowls, arranging the slices in a layered or fanned pattern for visual appeal. Let sit for 5 minutes to allow flavors to meld.
Garnish the salad with additional lime zest or a few mint leaves if desired. Serve immediately to enjoy the crisp texture of the fruit slices.
