2poundslarge cooked shrimp with tailsthawed if necessary
Pour enough grapefruit juice into six 4-inch mini fluted tube cake pans to almost fill pans. Freeze for 4 hours.
For Pink Grapefruit Cocktail Sauce, in a small bowl, stir together grapefruit segments, chili sauce, horseradish, and celery salt. Cover and refrigerate until ready to serve.
To serve, arrange watercress decoratively on a cake pedestal. Dip mini fluted tube pans in warm water until the juice rings release. Place juice rings on watercress on pedestal. Place a long-stem cocktail glass onto center of pedestal.
Fill bowl with Pink Grapefruit Cocktail Sauce. Arrange shrimp around ring.