Thaw shrimp and scallops, if frozen. In a large saucepan bring water and 1/4 teaspoon salt to boiling. Add shrimp and scallops. Simmer, uncovered, for 1 to 3 minutes or until shrimp and scallops turn opaque, stirring occasionally. Drain shrimp and scallops; cover and chill.
Meanwhile, set aside 1 cup of the chopped tomato, 1 cup of the chopped cucumber, and 1/2 cup of the chopped green pepper. In a large mixing bowl combine remaining chopped tomato, remaining chopped cucumber, remaining green pepper, the vegetable juice, green onion, jalapeno pepper, 1 tablespoon cilantro or parsley, lemon juice or lime juice, 1/4 teaspoon salt, and garlic.
In a blender container or food processor bowl cover and blend or process mixture, half at a time, until smooth. Return to the large mixing bowl. Stir in reserved chopped tomato, cucumber, and green pepper. Cover and refrigerate for at least 2 hours or up to 24 hours.
Just before serving, stir in shrimp and scallops. If desired, garnish each serving with additional cilantro or parsley. Makes 4 servings.