Use a chef's knife and cutting board to peel and cut fresh pineapple into small, bite-sized chunks, then place in a large mixing bowl.
Trim the watermelon and cut into similar-sized chunks as the pineapple, then add to the bowl with the pineapple.
Measure out and pour fresh lime juice over the mixed fruits, then sprinkle a pinch of salt. Toss gently with a spoon until evenly combined.
Transfer the fruit mixture to a serving bowl or plate, spreading evenly. Serve immediately to enjoy the fresh, juicy textures and vibrant colors.