Scoop the flesh out of the melon and chop into chunks
Using a vegetable peeler, remove 4 stripes of skin from the cucumber leaving a large stripe of skin between each. Cut cucumber in half lengthways, then cut into thick halfmoon slices.
Add the watermelon, cucumber and olives to a large bowl. Crumble over feta and tear off the mint leaves, tearing any large leaves.
Split the salad between 4 plates and dress at the table by drizzling with olive oil and squeezing over a quartered lime to each plate. You can combine the oil and lime juice beforehand if you prefer.