By Dave Conlin
Archeologist National Park Service Submerged Resources Center
Getting the equipment ready to go out on Discovery Diving's charter boat. (Photo: NOAA)
It was an early morning as our small team peeled off from the larger project to head out and collect corrosion and environmental data from the wreck of U-352. O-dark thirty and Brett Seymour (National Park Service photographer), Steve Sellers (East Carolina University Dive Office) and John Wagner (East Carolina University Graduate Student) and myself tried to sneak out of the dorm without waking our sleeping teammates. We arrived at one of Beaufort's two dive charter operators, Discovery Diving, a little before 7:00 and hauled rebreathers, stage bottles and a big box of scientific equipment onto the boat. It was only after I had made the last trip with my 70 pound rebreather that I noticed that the other guests on the charter had decided to use the dock carts thoughtfully provided by Discovery Diving-it was then that I realized that I should have had that second cup of coffee. Our skipper, Terry, didn't miss much, and although he was too polite to say anything, I was pretty sure he pegged us for bumblers right out of the chute.
Everything in nature seeks its own level, and what it true for water is also true for the Krupp steel that makes up U-boats. Our task today is to measure the corrosion rates at different areas of the submarine-this will give us both baseline data for the preservation of U-352, but also give us some scientific information that we can use to assist with its preservation in the future.
Corrosion of metal is really about electrons seeking their equilibrium by being transferred between the submarine and the seawater that surrounds it, and we have come up with a method to measure how many electrons are being transferred at any given location on the submarine. Because the U-352 is made up of many different materials, corrosion varies all over the wreck. All it takes to figure out how this is happening is three guys on rebreathers, a wire from the surface to the submarine for an electrical ground, a second wire from the surface to our silver/silver chloride corrosion probe, an Ocean Technology Systems through-water communications system, a full-face mask for me, so I can talk from the bottom to the surface, and a topside operator for the system, who can write down data as it comes up the wires (John Wagner).
"Either it will work or it won't," I said to Project Director, Joe Hoyt, in a stunning display of the obvious. As we unspooled lines, rigged equipment and wrestled ourselves into our equipment, I was pretty sure we were a distracting sideshow for the other passengers who would have rather focused on their own forthcoming dive. Captain Terry watched our preparations with a wry look on his face, and I couldn't help but wonder what he thought about our chances of success.
Dave Conlin, National Park Service, collecting corrosion data on the U-352. (Photo: NOAA)
As I jumped off the boat and my splash cleared, I could see the bubbles from the other divers below us through the clear water. "Com check John," I called out. "Loud and clear," came John's voice from the boat overhead. Step one-check! Steve and Brett were ahead of me, and Steve had the ground clamp ready to attach. I found a solid attachment point at the mount for the 88 millimeter deck gun and got a good connection. Step two-check!!
Brett started shooting pictures of the measurement process while Steve helped me manage the cables around the wreck. From last year's work, we had an excellent site plan and on it I had marked different locations where I was interested in assessing corrosion. John, topside, had a copy of the same site plan, and he wrote data values of electron flow, as I moved from one site on the sub to another. Step three-check!!! Our plan for corrosion assessment was working. "John I'm at location A, A as in apple," I called out over the communication system. "Okay, I have the reading, move on to the next point. 'B' as in boy. Okay, next." I moved over the sub, watching for urchins and getting really excited about the amount and quality of data we were getting.
Dave Conlin, National Park Service on the U-352. (Photo: NOAA)
Funny how your mind works 110 feet under the Atlantic Ocean- "John I'm at point R, R as in Rita." Rita?! I don't even know anyone named Rita. "I'm at point L, L as in... what the heck word starts with L... L as in love." On and on we rolled for 42 minutes, scanning the U-352 and sniffing the electrons flowing between the steel of the hull and the seawater that surrounds it. 42 minutes of pure data collection and heaven for an archeologist like myself. I could have stayed longer, but we needed to leave out of consideration for the other passengers, who had signed up for a day of diving, not corrosion assessment.
Back on deck, as I stripped my gear off and wiped the saltwater out of my eyes, Terry was on deck keeping a careful eye on returning passengers. "You did good down there," he said in a measured Carolina drawl, "and you half convinced me y'all know what you're doing." High praise indeed from our charter boat captain, high praise indeed.