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SCUBA Diving in Archaeological Research-What are the COMMENTARY Limits?

INTRODUCTION involve putting divers in the water. The ultimate William H. Charlton, Jr. question revolves around how best to use all of Officer or many long years men have dreamed of the new technologies and still conduct the high- Institute of Nautical Archaeology Fthe treasures that lay at the bottom of the est quality . seas as the result of shipwrecks. While crude Texas A&M University attempts have been made at salvage in the past, College Station, Texas some more successful than others, it was not ARTICLE until the advent of modem scuba equipment 'verecently read a recounting of the diving that thorough investigation of shipwrecks could Icareer of Wally Jenkins, a pioneer Navy diver be undertaken. Between 1984 and 1994, the and cave diver, in the February 2002 issue of the Institute of Nautical Archaeology at Texas A&M 's Alert Diver magazine University excavated a shipwreck off the Medi- (Viders, 2002). It was in 1956 that Jenkins and terranean coast of Turkey that was both the old- a dive buddy entered the 200 foot depths of est shipwreck ever discovered and the deepest near Tallahassee, Florida and shipwreck ever excavated on standard, open- discovered mastodon, mammoth and giant circuit, compressed-air scuba. This ship was from sloth bones accompanied by stone tools, which the Late Bronze Age, dated to approximately had likely been used by early man. "It was awe- 1305 B.C., and lay on a sloping, rocky seabed some," said Jenkins. That dive won't be consid- beginning at 140 feet-of-seawater (fsw) and end- ered an archaeological dive, but it was certainly ing slightly below 200 fsw. a dive of discovery that led to later archaeologi- As this excavation progressed from the cal research in the springs and cave systems early years, and the dive team realized there were of Florida. more and more of the shipwreck's remains As the for the streaming down the rocky slope, they wondered Institute of Nautical Archaeology (INA) at what effects the greater depths, that is, the Texas A&M University, I am constantly greater , would have on their bodies. reminded of our Institute's heritage. In 1960 a Remember, these were not Navy divers trained young University of Pennsylvania graduate stu- in deep-diving techniques, but diving archaeolo- dent by the name of George F. Bass led the first gists interested in digging into the past, and truly scientific study of a sunken ship with his many of them did not have a lot of diving experi- excavation of a Bronze Age (ca. 1200 B.C.) ship- ence. But they braved their fears and, using every wreck off of Cape Gelidonya, Turkey. Bass, the safety measure known to hyperbaric science at founder of INA and now retired from teaching that time, went on to complete a magnificent at Texas A&M's Nautical Archaeology Program, excavation that has added greatly to our under- is acknowledged around the world as the standing of life in the eastern Mediterranean "Father of Underwater Archaeology" for his some 3,300 years ago. pioneering application of sound, scientific, It is difficult to believe, but that project archaeological techniques to underwater exca- began almost twenty years ago, a time that, vations. according to some, was still in the dark ages of There aren't many similarities between . When we finished that excavation Wally Jenkins' dive into Wakulla Springs in 1956 in 1994 it was decided that, although there may and George Bass' excavation of a shipwreck in be more artifacts at deeper depths, we did not Turkey in 1960, with one very important excep- want to put our divers at any greater risk by tion. Both of these excursions into the water going deeper than 200 fsw. were made possible by the invention of the In the years since that project there modem self-contained underwater have been great advances in apparatus, known to one and all today as "scuba." and diving techniques, to include great varia- Without our scuba gear, most of us would still tions in mixtures. Also available be standing at water's edge wondering "what's in the last few years are new methods of looking down there?" into the deep that do not involve divers, mainly Now, at the beginning of the twenty- remotely-operated-vehicles, or ROV systems. first century, scuba diving is used in many dif- This article will look at these new technologies ferent research disciplines, including underwa- that will allow divers to work at much greater ter archaeology, , and oceanog- depths, and will compare them with the new raphy, to name just a few. Some underwater methods of underwater investigation that do not research is even conducted under extreme condi-

MTS Journal • Vol. 36, NO.3. 5 tions. Two examples that I am most familiar with Figure 1. Archaeologist/diver excavating copper ingots in are , who has made the center portion of the worlds oldest shipwreck dives to depths greater than 800 feet-of-seawater (1350BC) at approximately 150fsw depth. (fsw) as part of his fish studies around Hawaii (Richard took me on my first rebreather fam- dive on Catalina Island in 1995), and Tom Iliffe, a world-renowned submerged cave biologist from Texas A&M University at Galveston (I accompanied Tom on a wonderful research trip to the and cave systems of the Yucatan Peninsula in 2000). I am certain that and rebreather dives to 800 fsw are considered as extreme by most of the diving community. Speaking of extreme conditions, what are the limits of underwater research? Since I am an underwater archaeologist, I will address this question from the standpoint of my own disci- pline, although I am sure much of the discussion will apply to other underwater disciplines, as well. The Institute of Nautical Archaeology conducted a shipwreck excavation off the southern coast of Turkey between 1984 and 1994. This was the excavation of the oldest ship- wreck ever discovered (dated by dendrochronol- ogy [tree-ring dating] to 1305 B.C., during the Late Bronze Age), as well as the deepest ship- Center's F.G. Hall Hyperbaric Laboratory, ably wreck ever excavated (the shipwreck lay on a assisted by such hyperbaric research luminar- rocky, sloping seabed between 140 and 200 fsw) ies as Dr. Bill Hamilton and Dr. Caroline Fife. (Bass, 1987). I worked on this project for four What we in INA call "the Vann Tables" included years, and served as the project for in-water , a technique my last three years there. now routinely used by technical divers, but at While we were excavating what is that time considered as "pretty scary stuff." today known as "the Bronze Age wreck," our Our typical dive profiles on this project, diving was certainly considered extreme, and when diving on the 180 foot tables and shal- still is, by many, since we did it all on standard, lower, were two twenty-minute dives per day, open circuit, compressed air scuba. Excavation six days a week, for the entire three-month- in the early years was concentrated at depths long summer. The two daily dives were sepa- around 150 fsw, but as we became aware that rated by at least a five-hour surface interval and the wreck site continued deeper and deeper each dive was followed by twenty minutes of down the slope, concern grew over the increased decompression on pure oxygen at a depth of possibility of and increased twenty feet. When diving deeper than 180 feet nitrogen loading (figure 1). the dives were shorter and the decompression Hyperbaric science tells us that when was longer, as would be expected, but the major-

diving near a partial of oxygen (PP02) ity of the team did not dive to these depths, of 1.6 we are nearing the danger zone of oxygen especially the less experienced divers. Due in poisoning, and a PP02 of 1.6 is reached at 218 large part to the short amounts of time we could fsw when breathing air. Obviously those of us actually work on the site each day, the excava- who routinely dived the deep end of the wreck tion phase of this project took eleven years, or were at much greater risk of oxygen toxicity. more correctly, eleven three-month-Iong sum- We were fortunate the wreck site didn't extend mer excavation seasons (when most of your any farther down the slope. And yes, many of divers are either college professors or students, our divers were effected by , summer excavations become the only option). but those who chose to stay with the project During these eleven three-month summer sea- over the years became acclimatized and learned sons we conducted over 27,000 individually- to push through the narcosis and become pro- logged dives, and we suffered seven cases of ductive workers. "the Bends," or . On this project, though, we had one This has been a short overview of what very important safety margin. We were diving is, obviously, a much longer story of how the on a special set of dive tables formulated for us Institute of Nautical Archaeology conducted a by Dr. Richard Vann of Duke University Medical high profile excavation of an ancient shipwreck,

6 • MTS Journal • Vol. 36, No.3 but the reader should have a reasonable idea of to move around a very rough bottom terrain how the diving was conducted and the technol- would have been hindered by having to drag a ogy that was used to do it. I would now like to hose behind them. look at diving technologies and how The first newer technology that I want they might have effected how we worked on the to consider in retrospect, that would have Bronze Age wreck, and how they might impact helped us immensely, would have been the use future efforts at underwater archaeology. Also, of mixed gasses. The use of tri-mix, a mixture however, as any underwater scientist knows, of oxygen-nitrogen-helium that is formulated diving technology is not the only thing that specifically to your diving depth, allows deeper effects their work in the water. There are many dives on a much friendlier breathing gas than other "real world" topics that must be factored normal air. Even normoxic tri-mix (with the into the planning for any underwater project, same 20.9% oxygen as air, but with the nitrogen and I will try to look at a number of those. reduced by addition of helium) would have First, though, what is my familiarity reduced our decompression obligation even with diving technology upon which I might base more than the in-water oxygen decompression my opinions? I have been diving for over thirty already did. years, I am a Course Director My comment here is that mixed gas (Instructor Trainer Evaluator), I am a Diving diving, in my opinion, requires a whole new Safety Officer at a major U.S. university, an level of knowledge, experience, training, and American Academy of Underwater Sciences commitment on the part of . This, too, (AAUS) Scientific Diver, and a cave diver. I was would have reduced the number of divers eligi- certified as a Navy Scuba Diver while serving in ble to work on the project. Also, helium is either the United States Marine Corps. In the summer very expensive, or simply not available, in many of 2000, I served on the Staff of florida State parts of the world, thus eliminating any thought University's "Scientist-In-The-Sea" (SITS) Pro- of using tri-mix in many areas. gram. The SITS curriculum covers virtually And now let's talk about a type of equip- every type of diving technology in current use, ment that has been around for some time, but as well as an extensive look into the history of is only now becoming widely available at more diving technology. reasonable costs-the rebreather. As the name Let's look first at one way we could implies, these systems allow the breathing gas have achieved much greater times on the dive to be reused while constantly removing carbon site using a technology available at that time, dioxide from the exhaled gas. And because the that being to have turned the entire project into breathing gas is reused, and not exhaled away a saturation mission. During SITS-2000, we con- as bubbles, as with open-circuit scuba equip- ducted a two-day saturation mission at Ian ment, a rebreather's gas supply can last many Koblick's Marine Resources Development Foun- times longer than what an open-circuit diver can dation in Key Largo, Florida, during which carry, allowing much longer in-water times. Koblick and I discussed this option. And it's my Longer allowable bottom times would have understanding that this option was actually helped us immensely on the Bronze Age wreck. considered for this project, but dismissed. come in a variety of tech- I am of the opinion that our pool from nologies that are applicable to all depths, from which we drew divers for the project would have very shallow to very deep (remember Richard been much smaller had it been conducted by Pile's rebreather dives to 800 feet). This makes . I know a lot of underwater sci- them very attractive for underwater archaeol- entists who actually e!\ioy diving, but I also know ogy, and for any underwater science, for that some that do not. There are those who, matter. However, at the risk of repeating myself, although competent divers, really do not e!\ioy I must stress for rebreathers the same comment the diving aspect of their work. These consider I made about mixed gas diving, and that is that the diving as if it's getting on the bus to go to becoming a rebreather diver requires a whole work; they like their work, but they don't partic- new level of knowledge, experience, training, ularly e!\ioy the bus ride to and from. I can see and commitment from the diver. But more on many that did dive on the project electing not that shortly. to do so if they had to actually live under the It has often been said that the only way water to do it. There are also some negative to make scuba diving safe is not to put the diver aspects of trying to conduct such a saturation in the water. Under certain circumstances not mission in a foreign country that I'll address diving might be preferable, and there are great later. tools that can step in for the diver in these One other technology available at the cases-remotely operated vehicle systems, or time that was also considered, but not used, ROVs. In underwater archaeology a great deal was surface-supplied air. The great depth was of time is spent surveying, or looking for ship- one consideration, but also the divers' ability wrecks. A properly equipped ROV, i.e., with

MTS Journal • Vol. 36, No.3. 7 lights, cameras, etc., can take a great load off underwater archaeologists, or archaeologists-in- of the dive team in its efforts at locating and training, or at least with some underwater exca- investigating shipwrecks. Notice that I said vation experience, to conduct an excavation investigating shipwrecks, but not excavating within open circuit scuba, compressed air div- shipwrecks. ing limits. But at this point in time there may I think most underwater archaeologists not even be a total of forty diving archaeologists would agree that attempting to excavate a ship- with mixed gas training in the world to excavate wreck with an ROV would be fruitless. One of that 300 foot deep wreck. It will take time, but George Bass' pioneering ideas was to put the I am confident that, now that the technology for trained archaeologist on the sea floor. Pre- deeper diving is readily available, archaeolo- viously, an archaeologist had hired divers to gists who are interested in working deeper can investigate a shipwreck. The divers would look build teams of divers who are trained to do so. at the wreck and report back to the archaeolo- And now, let me talk about that one gist on the surface, who would then direct their bug-a-boo that concerns every archaeologist, excavation efforts. This must have been a frus- dry-land and underwater alike, and that is trating situation. Bass instinctively knew there money. I can honestly say that I have never heard was a better way, and before going off to Turkey an archaeologist say that someone was beating for his first underwater excavation, he took a down his door to give him money to do his YMCA diving course. The rest is history. work. Raising money is one of the most impor- Let's now look at the original question tant jobs of any archaeologist; if you can't pay of this article; what are the limits of archaeolog- for it, you can't go to the field. ical research in the water? We've just been talk- Just about anything to do with the more ing about ROVs, and ROVs can go quite deep. advanced types of diving, commonly referred In fact, a 1999 ROV search for a sunken Israeli to now as "," is not cheap. I have submarine in the Mediterranean Sea turned up already said that helium, for blending tri-mix, a 2nd centuIy B.C. shipwreck at a depth of nearly is very expensive (if it is available) in most areas 10,000 feet (phaneuf et al., website), but we of the world. And rebreathers, while they are can't excavate it. Why? Because we can't put the coming down in price, are still quite expensive. archaeologist on the wreck; its simply too deep. Would I like to have some rebreathers with It seems then that the limiting factor which to begin training underwater archaeolo- comes back to "man." How deep can the archae- gists for deeper diving? You bet I would. It only ologist go? We know that twenty years ago we takes money. What would I do if a benefactor were limited to depths of around 200 feet would say to me that he wanted to give me a because of our use of air as our breathing gas. half dozen Cis-Lunar Mark 5 closed-circuit But we have just discussed the modem rebreathers, with all the spare parts I needed, and to that limitation, mixed gas diving. This cate- all the carbon dioxide absorbent I needed? I gory actually covers both open circuit tri-mix probably wouldn't survive my heart jumping up diving and the rebreathers used for , and attacking me. since they are actually also mixed gas rigs. So And one other "real world" topic that how deep can the archaeologist go if he is a must be considered. Planning a project and mixed gas diver? packing up all your gear and driving off to do Here is where some of those "real your science in the water anywhere in the world" factors come into play. The diving archae- United States certainly has its own challenges. ologist who wants to go deeper must make the But planning a project in the commitment to spend the extra time and effort Middle East, where I have done most of my to get the proper training in mixed gas tech- underwater archaeology, is ever so much more niques, and if he will be using a rebreather, to complicated. Imagine trying to ship a saturation be trained on that specific rebreather rig. But habitat and all its associated equipment into a no matter how deep he can go, no single diving country where the Customs officials may not archaeologist has ever completed a shipwreck even know what basic scuba gear is. I was once excavation. On the excavations I have partici- told by a local diver in one country where I was pated in the dive team has usually included working that we would never be able to bring somewhere between fifteen and forty divers. rebreathers into his country because only their Can we put together a team of between fifteen navy special operations divers had them and and forty mixed-gas trained diving archaeolo- we simply would not be allowed to bring them gists to excavate a shipwreck at a depth of, say, in. You just have to work within the local guide- 300 feet? lines of wherever it is you are working. Here is an appropriate place for com- This seems like a long way around to ments about staffing the underwater archaeology come to the conclusion that, even though modem team. In my experience it has not been difficult diving technologies will allow us to go much to attract qualified divers who are trained deeper than just a few years ago, the technology

8 • MTS Journal • Vol. 36, No. 3 itself is often not the governing factor. Training REFERENCES requirements are so much more important in technical diving, and this type of diving requires Viders, H. 2002. Man of Honor. p. 32. Bass, G. Bronze Age Shipwreck. National Geographic an entirely new mind-set. And money is more Magazine. 1987. 172:6, pp: 692-733. important than ever. However, I am confident Phaneuf et. al, Special Report: Deepest Wreck. Archae- that with greater effort and preparation on our ology website. www.archaeology.orgl parts, those of us interested in diving deeper found. php?page/O 103/etc/wreck.htrnl into our archaeology, or any other underwater science, will be able to do so in the future.

MTS Journal • Vol. 36, No.3. 9