Heat oil in a deep fryer to 350 degrees. In shallow dish combine crackers, garlic salt, and 1 teaspoon of old bay seasoning. In another bowl mix egg, water, ¼ teaspoon old bay seasoning and salt and pepper to taste.
First coat each fish fillet in the egg mixture, and then put the fillet into the cracker mixture and coat well pressing down so the crackers stick. Repeat until all the fillets are coated.
Deep fry in batches at 350 degrees for 2-3 minutes or until golden brown and crispy. Drain on paper towels.