As I recall, they were outfitted with the shipping plugs emike speaks of. They have a perfect example inside the Fort Fisher museum from the Ella.
The Underwater Lab is not open to the public. People can't just walk up and go in. But, I would imagine if you called and requested a tour or look inside, they would probably oblige if your time schedule was flexible. I attended a seminar which included a walkthrough of the lab and some storage areas. A friend of mine was the key to the back room. Incredible stuff in there. I made some images which I will upload soon. I even have pictures of the whitworth case shot shell that was a matter of discussion some months ago.