Watermelons are int he same family as cucumbers, so it's a natural. Not a sweet or a dessert, but definitely watermelon-y, and a good way to use up bits and pieces of the other veggies
4-6 c cubed waterlmelon(seedless)
2 peeled, seeded, diced tomatoes (or 1 c tomato puree)
1/2 green bell pepper ( or a yellow, or a red)
2 Tbs diced sweet onion
2 c salt-free cold chicken stock, or vegetable stock
Salt and pepper to taste
Throw it all in the blender, food processor or in a bdeep bowl and use your hand blender and puree until it's the texture you like--smooth or chunky. Season to taste, and chill. Just before serving, you can drop in a dollop of plain yogurt, sprinkle with fresh herbs like parsley, thyme, lemon thyme, basil, etc.
It's not the destination, but the journey!