In a large bowl, combine the crab meat (broken up), shrimp, red onion, and celery.

In a small bowl whisk together the mayonnaise, lemon juice, Old Bay Seasoning, fresh dill, and salt. Taste and add salt and pepper to taste.

Stir the dressing into the main ingredients and serve. This recipe can be stored in the refrigerator for up to four days in an air tight container.