Arrange the sliced peaches and watermelon cubes in a large mixing bowl, spreading them evenly to showcase their vibrant colors.
Gently tear the fresh basil leaves and scatter them over the fruit, creating a layered, aromatic appearance.
Sprinkle the coarse sea salt evenly over the fruit and basil, allowing some salt crystals to sparkle on the surface. Using a large spoon, carefully toss the mixture just until the fruit releases some juices and the basil is evenly distributed, ensuring a spontaneous, juices-overflowing appearance.
Allow the salad to sit for 2 minutes, letting the juices mingle and the flavors to meld, with visible pooling of fruit juices and basil aroma wafting up.
Serve immediately in bowls, showing juiced-up fruit and basil leaves, with some juices dripping down and a glistening surface.