To make the dressing, place the orange juice concentrate, vinegar, and water in a blender; blend on low speed. Slowly drizzle the olive oil into the blender until mixture thickens slightly. Season with salt and pepper. Refrigerate until ready to use.

To make the seafood salad, place the lobster, shrimp, and crabmeat in a bowl. Add 2 tablespoons of the dressing and toss until seafood is coated.

Divide the salad greens among 6 plates or mound on one large platter. Place the seafood mixture on the greens. Alternate the grapefruit sections, kiwi slices, and pineapple and tomato wedges on the plates. Serve with the remaining chilled citrus vinaigrette on the side.