Combine first 8 ingredients in a small saucepan. Bring mixture to a boil over medium-high heat, stirring constantly; boil 1 minute.
Pour mixture through a wire-mesh strainer into a small bowl or jar, pressing mixture against sides of strainer with back of spoon; discard seeds and pulp. Cover and chill.
Arrange lettuce leaves evenly on 6 salad plates; arrange watercress sprigs and orange sections evenly over lettuce.
Drizzle 1/4 cup raspberry mixture over each salad; sprinkle evenly with almonds.