In medium bowl mix gelatin with water; let stand 1 minute. Pour boiling clam juice over gelatin and stir until completely dissolved. In small bowl mix mayonnaise, mustard, salt and Tabasco(r) sauce; stir into gelatin mixture. Chill until the consistency of unbeaten egg whites. Stir in crab meat, cucumber, red and yellow peppers and scallions. Fold in whipped cream. Turn mixture into a lightly oiled 4-cup mold. Chill until firm, at least 4 hours. Flavors will blend if refrigerated overnight. Unmold and serve with crackers.