Preparation Whisk orange juice and 1 1/2 tablespoons vinegar in medium bowl to blend. Whisk in 1/4 cup oil. Season with salt and pepper. Cut peel and pith from oranges; cut between membranes to release segments. Whisk 1 tablespoon oil, orange peel, lime peel, lime juice, pepper, and 2 teaspoons vinegar in bowl for marinade. (Dressing, oranges, and marinade can be made 4 hours ahead; chill. Bring dressing back to room temperature.) Mix scallops into marinade. Let stand 10 minutes. Heat large nonstick skillet over high heat. Add scallops with marinade and sauté until just cooked through, about 2 minutes. Season scallops to taste with salt. Toss orange segments, mixed greens, and tomatoes in large bowl with enough dressing to coat. Divide salad among plates. Place scallops atop salads.
Preparation Whisk orange juice and 1 1/2 tablespoons vinegar in medium bowl to blend. Whisk in 1/4 cup oil. Season with salt and pepper. Cut peel and pith from oranges; cut between membranes to release segments. Whisk 1 tablespoon oil, orange peel, lime peel, lime juice, pepper, and 2 teaspoons vinegar in bowl for marinade. (Dressing, oranges, and marinade can be made 4 hours ahead; chill. Bring dressing back to room temperature.) Mix scallops into marinade. Let stand 10 minutes. Heat large nonstick skillet over high heat. Add scallops with marinade and sauté until just cooked through, about 2 minutes. Season scallops to taste with salt. Toss orange segments, mixed greens, and tomatoes in large bowl with enough dressing to coat. Divide salad among plates. Place scallops atop salads.