The pot should have a raised rack of a minimum of 2". Add equal amounts of vinegar and water to just below the rack. Layer crabs and sprinkle each layer with a mixture of salt and seafood seasoning.
For Each dozen crabs mix 2 1/2 tbsp. seasoning and 3 tbsp. salt.
Steam approximately 15 to 20 minutes after water returns to a boil and starts to steam.