Place shrimp in a large bowl. Season well with salt, pepper and seasoning salt.
Heat 3-4" of oil in a Dutch oven or deep fryer to 350 F.
Add panko to a pie plate or shallow dish.
Season with salt, pepper and seasoning salt and stir.
In a separate pie plate or shallow dish place the flour.
Season with salt, pepper and seasoning salt and stir.
In a small bowl whisk together the egg and water.
Dip the shrimp in the egg and water mixture and coat. Shake off excess.
Add the shrimp to the flour. Toss to coat. Shake off excess.
Dip again in egg and water mixture. Shake off excess.
Toss shrimp in panko crumbs. Coat well.
Working in batches if necessary, add shrimp to the hot oil and fry 3-4 minutes, turning once. Remove to a paper towel-lined plate to drain.
Serve with lemon wedges, cocktail sauce or tartar sauce.