Combine lime juice, marmalde, oil, salt & pepper in a blender & process until creamy. With the machine running, slowly add the water & process till creamy. Set aside. Line a shallow bowl with lettuce. Alternate circles of radish & orange slices over the top. Cover & refrigerate. At serving time, peel, pit & cut avocado into 1/2" dice. Add to the top of the salad & drizzle with dressing. Serve immediately, as is or tossed. Yamuna Devi, "Yamunas Table"