MR. KOJO NNAMDIIn June 1788, Joshua Barney, a revolutionary war naval hero, set out to deliver a huge thank you gift to George Washington. Barney left from Baltimore on The Federalist, a 15-foot miniature ship crafted by the city's merchants in appreciation of Washington's work with the constitutional convention. The boat was docked right outside Mount Vernon. But just a month later, a severe storm swept through the area and sank the boat. The Federalist is just one artifact underwater archeologists are seeking as they map out the Potomac, the Patuxent and their tributaries using sonar and science. Researchers are quietly uncovering the area's lost history and documenting their findings. It's dark, dangerous work that largely goes unpublicized since scientists don't want treasure hunters looting their discoveries. So, what's down there and what are we learning from these sunken sites? Joining us to have that conversation is Esther White, director of archeology at Mount Vernon. Esther, thank you for joining us.

MS. ESTHER WHITEThank you, Kojo.

NNAMDIAlso with us is Bill Toti, project manager for the Institute of Maritime History's Mount Vernon underwater archeology project. Bill Toti, thank you for joining us.

MR. BILL TOTIThank you, Kojo.

NNAMDIAnd Susan Langley is back. She is underwater archeologist for the State of Maryland. Susan Langley, good to see you again.

MS. SUSAN LANGLEYPleasure, Kojo.

NNAMDIYou too can join the conversation at 800-433-8850. Esther, in an area so rich in historical significance, you'd think that archeologists have been over this area with a fine-toothed comb. But underwater exploration just started this year at one of the most important American historical sites in our area. Why are we just now exploring what's off the banks of Mt. Vernon?

WHITEWell, exactly. We've been doing archeology at Mt. Vernon since 1987. But it was just this past year that we were approached by the Institute of Maritime History, and they had a wonderful plan to come and survey the Potomac River, from Little Hunting Creek to Dogue Creek. And we thought it was a great opportunity to find out what was out in the Potomac and inside these two creeks.

NNAMDII think many of our listeners know George Washington as a gentleman farmer, but his largest business at Mt. Vernon was actually fishing. Tell us about that business and how it coincides with the exploration going on in the Potomac.

WHITESure. Well, Mt. Vernon had, during Washington's time about 10 miles of shoreline. And along these 10 miles, George Washington had three fisheries set up. And every spring, the slaves would go out and would use very, very large seine nets to catch shad and herring and white fish and other things. In certain years, he harvested over a million fish from the river and these were sold for lots of money. And it was his largest industry.

NNAMDIFishing was number one. Milling was number two. Distilling, number three.

WHITEAt the very end of his life, distilling took third place.

NNAMDIAnd then farming.

WHITEAnd then farming, exactly.

NNAMDIIt's my understanding that during the short fishing season, he instructed his slaves to fish both day and night.

WHITEThat's right and...

NNAMDISo he'd end up with a million fish, yes? Mm-hmm.

WHITEWell, exactly. It was just a very large operation. And, you know, all hands on the plantation stopped what they were doing, and everyone came to harvest this fish and get them packed into barrels with salt, so then they could be used both for food, for the people living at the plantation, and also sold in Alexandria, and sold as far away as the West Indies.

NNAMDIBill Toti, you led the team that went out in April to explore the water around Mt. Vernon. What were you looking for?

TOTIWe were looking for anything of historically -- historic significance, any cultural artifacts we could find at all. We ran over 80 miles of sonar scans in the river from a few miles north of Mt. Vernon to a few miles south, and mapped those anomalies and then tried -- to dive on as many of those anomalies as we could. That was -- our time ran out though before we could get to many of them.

NNAMDIDid you find any sign of the Federalist?

TOTIWell, we don’t know is the short answer. We've certainly found sonar signals that may indicate that a boat of the Federalist size is present. It’s not gonna be until we dive the -- over 100 anomalies that we found or we know for sure whether we found the Federalist.

NNAMDIEsther, what do you hope to learn about Washington's fishing industry from the underwater exploration?

WHITEWe'd love to find evidence for where these fisheries were located. We have an idea where they were, but we don't know their exact location. In Florida, some of the partnering professional underwater archeologists that were helping us have found wonderful evidence of planking of fisheries like this, wharfing, things like that. And then just -- if we could find any information about Washington's maritime interest. He owned several boats. Boats were very important to the operation of the plantation. And then, of course, the Federalist would be just a great thing to find.

NNAMDIWe're interested in having you join this conversation at 800-433-8850. What famous shipwreck have you always wanted to see? 800-433-8850. Have you ever found or thought you found an underwater shipwreck in our area? You can also send us a tweet, @kojoshow, e-mail to kojo@wamu.org, or join the conversation at our website, kojoshow.org. Susan, can you talk a little bit about what the diving conditions are like in the Potomac?

LANGLEYWe call it archeology by brail. (laugh) It's very murky almost all the time. If we have a drought for a few weeks and, obviously, this last few August we've had, you know, fairly dry weather, we would get fairly clear visibility. And sometimes in the winter when it's very cold, things settled down. There's not as much biological growth in the water. But if it so much as rains in West Virginia, by the time, you know -- within a few days, that flow will come down and it will silt us out. So a lot of it is -- you need a lot of skills and patience, and you can't be scared of the dark.

NNAMDIIt’s also pretty dangerous, can it be not? Can it not be pretty dangerous also?

LANGLEYIt can. We don’t encourage anyone including myself, my staff. We don’t go inside of wrecks in -- you know, unless one really has to. And, in fact, we've never have at this point because of entrapment possibilities getting silted out. We do worry about -- we always counsel divers go down feet first very cautiously as opposed to diving down for head first in case there's sharp objects or tangles of metal. And there are areas where we know there is a substantial amount of debris that one must be cautious about -- post piles, tree trunks. So, yeah, we're very carefully how we do it. Safety is a number one concern.

NNAMDIBill, how well preserved are the aforementioned anomalies that you found? And how can you tell what they are?

TOTIWell, there's good news and there's bad news, Kojo, when you about -- wrecks and in a river like the Potomac. The good news is fresh water tends to preserve better than salt water does. The bad news is the more oxygen in the water, the quicker the decay. And in a shallow river like the Potomac, there's a lot of oxygen in the water. So those two things kind of balance out. Some of the Civil War wrecks we've dove on are remarkably well preserved. Some of the 20th century wrecks that maybe in more oxygenated water surprisingly not well preserved. So it depends exactly on the chemistry of the water surrounding that wreck.

NNAMDIRemember you can call us at 800-433-8850. Are you a diver who has seen interesting things in our local waterways? 800-433-8850. Susan, I interrupted you.

LANGLEYOh, it's okay. I was going to say the faster they get buried, the faster an organic matter, whether it’s wood or cloth or whatever we might be interested in, fish remains -- the faster they get buried in the sediments, the quicker the oxygen is choked off and the -- sights the wood will reach an equilibrium with its environment in sort of a stasis. So a lot of the time, people say, well, if we don’t dig it up, if we don’t raise it, it's gonna rot away. We'll never -- actually, opening them up can be detrimental. They're often very well preserved, sealed off as they are. So we need to be aware of that, too, when we're excavating how important is it to really open this site.

NNAMDIHow badly do currents and drifting affect shipwrecks? Is it possible that the Federalist, for instance, has drifted far away from Mt. Vernon?

TOTIWe did a bit of analysis on how much a 15-foot boat and that's as big as Federalist is. It’s only 15 feet long. It would have drifted in the storm that George Washington referred to in his diary as a perfect hurricane. And we're pretty convinced it would have swamp before it got too far, so probably, in no more than a couple of miles down river, downwind from Mt. Vernon. And once it swamped, it would've gone down quickly. And as Susan indicated is -- if the sediment built up around it, it probably would not have moved much after it hit the bottom.

NNAMDIOn to the telephones. We start with Janice in Washington, D.C. Janice, you're on the air. Go ahead, please.

JANICEHi, Kojo. Thank you so much for taking my call. I have to confess that I'm a life-long -- pretty much, Virginia resident. And I'm -- did not know that George Washington's major source of income was from fishing. And -- but I do know and remember that he was an excellent business man unlike many of our founding fathers. So although your guests are more -- are seeing more from the archaeological points of view, I just wanted to hear a little bit more comments about the role of fishing in his fortune and, also, maybe a little comparison to somebody like Thomas Jefferson, who died, unfortunately, broke. And I'll take my answer off the air. And thank you again.

NNAMDIYou're welcome. Here's Ester White.

WHITEWell, Washington -- of course, you know, the Potomac River is just -- was very, very important to the entire operation at Mt. Vernon. The slaves on the plantation were given 20 herring a month as part of their rations. And so, you know, these fisheries provided food for the enslaved community. Washington was selling the fish, you know, barrels of salt fish, the herring and the shad, and Alexandria -- and, you know, making some years -- 1772, you know, 140 pounds sterling from selling that fish. And then, of course, he's just always -- you know, I think, one of the things about George Washington is that he is very inquisitive. He's always looking to improve things. He's very involved in all aspects of running the plantation.

WHITEHe's starts out with a seine net, a very large net that is 210 feet long. And, just in the 1770s, when he's quite involved in fishing, increases the size of the nets, and, you know, orders one that's 350 feet. And then finally ends up with, I think, a 450-foot net, that is being taken out into the river to bring fish back in. And so, you know, he's very prepared to tweak the operation. He's very involved in things. He knows exactly, you know, how many fish are coming in every day. And I think that into aspects like that, that really make you, you know, a sound businessman.

NNAMDIOn to Michael in Woodstock, Md. Michael, you're in the air. Go ahead, please.

MICHAELGood afternoon. I'd like a -- piece of information. I think the river used to be a lot narrower and deeper, because of the trees and foundations out in the water. Did it silt up from agriculture or something like tobacco or logging, you know, timber removal? Was it once deeper, say, 250 years ago, and narrower?

NNAMDISusan?

LANGLEYIt was. I don't know it was -- I don't think it was substantially narrower. We're also looking at sea level rise, which over the -- you know, has helped a lot -- or hindered a lot, depending how you look at it. But you're absolutely right about the deforestation. Colonial agriculture was -- used the old feudal system. They often plowed perpendicular to the river. So when there were heavy rains, it washed the sediment in, it -- that, which was detrimental to the oystering industry and some of the fishing industry because it's stifled the eggs. It wasn't until the -- surprisingly, late in the 1800s that they'd begun to conjure a plan in some areas, not even until 1900s, conjure a plan to prevent soil running off. And so the deforestation and poor colonial farming practices did contribute to silting it up extensively. There has been erosion on the shorelines, and, as you say, about noting the foundations out in the water. And then, now, sea level rise is also contributing to that. So, yeah, you're right.

NNAMDIWe had an e-mail from Eric who had a question about that, and another question writes Eric, "Does the regular dredging we do of some local water waste help or hurt treasures hidden in the muck below?"

WHITEExcellent point. We actually do work with major dredgers -- will be the core of engineers usually, port authorities. And they do work with the State -- the State Historic Preservation Office, which is also the Maryland Historical Trust, all within the Department of Planning. And they -- and in Virginia, they have a counter agency. In Maryland waters and Virginia waters, you must have a permit to this. The core of engineers speaks to us. And we're looking our records and see if it's been previously dredged -- certainly there's been damaged done in the past. If it's an area where we feel there's a high potential for historic resources, we can ask them to do a survey, to do archeology. We don't do it for them, because we -- since we've mandated it, they can't then pay us. It would be very nice if it worked that way, but it doesn't. They will hire a consulting firm that will investigate that, so that we don't inadvertently damage artifacts. And so, yes, dredging does go on. But anytime it's new dredging or deeper dredging or broadening or changing channels, that will be investigated before it happens.

NNAMDIOn to David in Washington, D.C. David, you're turn.

MR. DAVID JOHNSONHey, Kojo. Thanks for taking my call. I'm a professor to American University and one of the board members of the Institute of Maritime History. And I just wanted to call in to say thanks for giving some time to express this information. Say hi to Bill and Esther and Susan.

NNAMDIOh, this is David Johnson?

JOHNSONYes. (laugh) And...

NNAMDIHi, David.

JOHNSONI just wanna say, you know, it's fantastic to get this kind of exposure on a show like yours, so we can talk about the issues that we face and clear up some of the misconceptions. And. certainly, I'd like to extent an invitation to anyone who's interested in this type of work. IMH is a group that trains a vocational archaeologist. Anyone who's interested, who wants to come and dive with us, we've got a number of projects going around the Chesapeake. And we'd love to see you come out and help us do some of the good works that helps us capture this knowledge. Washington, you know, is more than just a maritime enterprise. It -- his own plantation, of course. He was one of the first land speculators recognizing the importance of the sea, you know, canal, to build waterways that could move goods throughout the country. And certainly, we're doing a lot of work in the Chesapeake to document the great maritime history that's here and we'd love to see as many people as possible come join us.

NNAMDIDavid, thank you very much for your call. And that gives me the opportunity to have Bill Toti talk a little bit more about the institute, because the Institute of Maritime History, IMH -- and we have a link at our website, kojoshow.org -- has located shipwrecks off the U.S. Marine Corps Base at Quantico. Tell us about these discoveries, their history.

TOTIWe have projects actually going on all the way from Maine to Florida. And as David indicated, IMH is a mostly volunteer ad vocational with professional archeologists on the staff such as David. So we always dive supervised by professional archeologists particularly when we're in later phases of exploration and always we have professional archeologists on scene if we're ever asked to do any recovery of artifacts. Our trademark is don't talk, don't take. So we are very much against the for-profit treasure hunters that do work that they claim to be like ours, but it actually is for their own personal profit. Most of the IMH folks are volunteers who do this on their own time and at their own expense. That makes us very reasonably priced. But we are -- we've discovered archeological finds off Quantico and other places, in the Patuxent, in the Chesapeake and in the Potomac. And so we're always looking for money and volunteers.

NNAMDIWell, a lot of people I suspect would really understand the don't take aspect of that. What do you mean by the don't talk aspect of that?

TOTIWe do not want anybody to know what we found, where we found it, because we're afraid then that other folks might go down who don't have preservation in mind and take. And so, for example, I found some very intriguing artifacts last summer on a site in a local river and photographed them, documented them, and then left them. And that's kind of our motto.

NNAMDIDon't say where they are. And Susan Langley, this one for you. We got an e-mail from Katie in Odenton, Md., who says, "I'm a diver and never knew Maryland has a state underwater archeologist. I'm betting my teenage daughter, who was certified a scuba diver this summer, would love to add this to her list of possible jobs in her future. What is your education background? Are you a historian or a marine biologist or something else?

LANGLEYSomething else. My bachelor's degree is in anthropology with a specialization in archeology. My master's was in law and archeology. My PhD is in underwater archeology. So it's a little bit of everything. If your daughter is really interested, computers are the way to go. We do a lot of remote sensing, electronic remote sensing. Rather than putting divers into low visibility, we like to see where the sites are remotely. It's safer and it saves time and money. So I encourage anyone interested in the discipline to really get a good background in computer programming and -- much more so than we used to have. I rely heavily on having very talented people around me most of the time that can process these data.

NNAMDIKatie, thank you very much for your e-mail. I'll charge a finder's fee if your daughter gets a job in this field. In this time of budget crunches, Susan, is it difficult getting -- finding funding?

LANGLEYIt is. Although I have to say our -- my program has been very fortunate and we're also, you know, in the enviable position of having non-profit organizations like IMH be around in this area. Those folks are very, very generous with their time. We have been able to in the past provide non-capital grants to them, two of them. And our return on that investment was they surveyed over 107,000 acres for us. And they can also save me time and money by coming back and saying, we looked at these 12 anomalies. This one is modern debris, that one is a fiber glass boat. Those three, you'd better have a look at. And so it's huge return on our investment. Unfortunately, those monies have gone away with the budget cuts. They will come back when times get better. We have a few groups who are actually working to see if we can't move that forward a little bit.

NNAMDIAnd David Johnson, thank you for your call.

JOHNSONThank you, Kojo. Take care.

NNAMDIWe are gonna be taking a short break. When we come back, we'll continue our conversation on underwater archeology in the Washington area. But you can still call us, 800-433-8850. Are you a diver? Have you seen interesting things in our local waterways? 800-433-8850 or join the conversation at our website, kojoshow.org. I'm Kojo Nnamdi.

NNAMDIWelcome back to our conversation about underwater archaeology. We're talking with Bill Toti. He is project manager for the Institute of Maritime History's Mt. Vernon underwater archaeology project. Susan Langley is underwater archaeologist for the State of Maryland. And Esther White is director of archaeology at Mt. Vernon. Esther, what's next for the Mt. Vernon project?

WHITEWe are hoping that the IMH will come back. We were hoping that they'd be back in November. But it looks now like they'll be back maybe in February or March when they're in the Potomac doing some other work. The hydrilla was very bad last spring, and so we need to get them back in colder weather when we can get into some of the shallower water.

NNAMDIIf you find The Federalist, Bill, are there any plans to raise it?

TOTIIf we find The Federalist, the next step would be raising the money that would be required to preserve it because that has to happen before we raise anything.

NNAMDIOkay, so you -- if you raise the money -- it's conditional. If you raise the money, chances are, you will.

TOTIWe would. We'll absolutely be very anxious to raise it.

NNAMDIMaryland has been a focal point of work for the Institute of Maritime History. You mentioned that you work all over the country. But this adds a little bit to what David Johnson has been saying. Tell us about SHIP, your Submerged Historical Inventory Project.

TOTISHIP is an organization that's based out of Florida, out of St. Augustine, Fla., where a great deal of archaeological work goes on, as you might expect for one of America's oldest seaports. And there's a great group of professional archaeologists down in Florida that support us as well with both equipment and their time and expertise. And so we are tied in with SHIP very tightly.

NNAMDIWell, we got a tweet from Jay, who asks, "If future dives result in the identification of collections of artifacts, how and where will they be processed, housed and displayed?"

WHITEDon't look at me. (laugh)

NNAMDII'm looking at Bill now. (laugh)

TOTIWell, you know, we think that probably the organization that helps generate the money for preservation would be -- would probably gain rights to displaying them.

NNAMDIWell, before we go back to the telephone, Susan, you've been exploring another noteworthy shipwreck in the Patuxent River near Upper Marlboro this summer. Bring us up to speed on your search for the Chesapeake flotilla and, specifically, the USS Scorpion.

LANGLEYAll right. That's a large project that is being undertaken in partnership, of course, with Naval History and Heritage Command because the vessels in that area -- and to back up for a moment, Joshua Barney scuttled his flotilla when -- in August of 1814 when he went to the aid of Bladensburg and tried to hold the line there for the attack on Washington and scuttled a number of the vessels there, and the USS Scorpion would be his flagship. There has been exploration in the past by Nautical Archaeological Associates and the Calvert Marine Museum back in '79 and '80. And the Navy is interested in revisiting the site. We're doing it in partnership with the State Highway Administration. So it's Dr. Robert Neyland with the Navy, Dr. Julie Schablitsky with State Highways and my office and myself. So it's three chiefs. We're gonna try and balance this act out, but we're doing very well. And we are indeed looking for the Scorpion. We have solid indication and have done some exploration that there are certainly more than one vessel, though I can't say how many yet. But we're surprised at the evidence we're finding. And it's a multiyear project with, we're hoping, a very large excavation in 2012. And again, it's fundraising. We have -- we expect this project -- it started this summer -- will run through 2016 and will cost about $4.6 million, of which we've raised more than half.

NNAMDIBill Toti?

TOTIAnd, Kojo, that Commodore Joshua Barney that Susan just spoke of, this is the very same Captain Joshua Barney who sailed The Federalist up to George Washington's Mount Vernon. He was not just a revolutionary war hero but a war of 1812 hero as well.

NNAMDIBack to the telephones now. Here is Irene in La Plata, Md. Irene, your turn. You're on the air. Go ahead, please.

IRENEIt sounds to me like your presenters are only interested in wrecks. Is that correct? Are they interested in fishery? Because there's an extensive fishery historical background at Chapman State Park located in Charles County.

NNAMDIHere's Susan Langley.

LANGLEYActually, we're interested in prehistoric, historic sites, certainly places like Historic St. Mary's City. We're interested in historic landings. And we are interested in fisheries and, in fact, have had a number of private citizens identify fish weirs for us in areas we hadn't expected to find them. In the Upper Potomac, we've also had people find indication of 19th century fisheries for us in both Charles County and St. Mary's County. So we are certainly interested in mapping and recording these. Obviously, a fish weir is not as easily, you know, taken out and preserved. They're obviously something that we study in situ, in place.

IRENEOkay. Well, I thought there might be some -- certainly, that is a -- it's on the national historical register, and it's titled -- it is located in Charles County.

LANGLEYYes, ma'am. We're well aware of them and we consider them significant resources.

NNAMDIThank you very much for your call. Getting back to the flotilla for a second, Susan, could we see part of this flotilla exposed in time for Maryland's bicentennial commemoration of the war of 1812?

LANGLEYThat's one of the goals. Certainly it is. We were hoping to do a public excavation in the summer of 2012 and have the -- so that everyone can come and visit and have any artifacts retrieved from that site conserved, and that's -- takes a lot of time and money, conserved and ready for traveling exhibits by 2012 -- or by 2014, which is Maryland's big show. So in 2012, we will be undertaking the work. By 2014, which, of course, is when the bombardment of Baltimore and the Star Spangled Banner, that's when we expect -- and when all these activities, the burning of Bladensburg, the scuttling of the flotilla, the burning -- we're all in August and September of 1814, so that's -- really for us, 2014 is the most significant year. So we're hoping to have everything publicly available, publications, films, everything by then.

NNAMDIWell, this might be a dumb question, so tell me if it is. But you've -- you're required to dam off the site and excavate the vessel under dry conditions. How do you dam off an archaeological site in the middle of the river, suck the water out and expose it for public viewing?

LANGLEYCofferdamming has been used successfully in a number of places including -- in some places I've left it wet, as in Virginia tried this a number of years ago around Revolutionary Warship, the Betsy. Texas has done it with La Salle ship, the La Belle. And it is a double-walled cofferdam with sand in between. It's not 100 percent dry. We don't want it 100 percent dry. That would be bad for the wood. But it would be exposed while we work on it and flooded thereafter to keep it moist and then brought down to work on it. It isn't a 100 percent -- the best way to go for a -- for the wood itself, but it would be a good way to study it, monitor the site after and see if we can get it back to stasis and see what's in there and make it publicly available, because that's one of the things people worry about with underwater archaeologies. They don't get to see what's happening. And we can't really run a video like you can in beautiful clear waters like Florida. So one way to make it available is to do a -- an open excavation. And we have other agencies interested in helping us do tele-presence to various areas when people can't come into classrooms.

NNAMDIHere is Don in Woodbridge, Va. Don, you're on the air. Go ahead, please.

DONYes, good morning, Kojo. Thanks for having me. I just had a comment and a quick question. Comment, he wouldn't be here had it not been for about three separate shipwrecks off the Atlantic Coast way back a long time ago. But I just was wondering if our guest could answer this question. Is there any kind of a database that might be publicly available that would list the shipwrecks that have been discovered or somehow noted?

NNAMDISusan.

LANGLEYWe are working on that. In fact, that's one of the projects that IMH is helping us with and we had some other entities. We're working on putting together a database trying to figure out a way to make it publicly available without necessarily giving out detailed locations for, you know, the protection of the sites themselves, but at least letting folks know roughly where -- in points of interest. There are -- not every site is -- hate to say it, not every site is sacred. We don't preserve the locations of all. Many of them are publicly visited. You know, we encourage visitation. But we can't give out the locations of all of them, but we are trying to work on some form of public access. And there a couple of folks in the private sector, and I can't tell you which the organization is, who've been in touch with me about producing maps of the wrecks. And I'm sure you've seen them in Ocean City and Delaware of all the wrecks down the coast. And they're trying to update some of those and make those available as well. National Park Service and the National Register are open to the public, and they will list sites that have been recognized as significant at various levels.

NNAMDIAnd, Bill, colonial shipwrecks aren't the only vessels lying in the bottom of our ward, because we even have some German U-boats lying around. Tell us about the Black Panther Shipwreck Preserve.

TOTIThe U-1105, Kojo, is a U-boat that the United States captured near the end of war, towed to the Washington Navy Yard in Washington, D.C. and to the Naval Research Lab and exploited it. And some time after the war, the submarine was towed back down to -- near the mouth of the Potomac and sunk intentionally with one of the first tests of an anti-submarine warfare torpedo. And, Kojo, I'm a retired submarine captain, so that wreck in particular is very intriguing to me. We help Susan and her office preserve that submarine and to the point that was made earlier about preservation, unfortunately, some of the pieces of that submarine have been taken by divers. It's very unfortunate that happened, But we do our best to help preserve and protect it.

NNAMDIWhat did we learn from the U-boat when divers rediscovered it in 1985?

TOTIWell, one of the things that fascinated me as a submariner because it -- I'd never read any reports of this, is that the U-boat is covered with what we call anechoic coating, which is rubber coating that was intended to reduce the sonar reflections and make it less detectable by American Forces. The reason that was so intriguing to me is our boat -- our own boats were not covered with anechoic coating until the 1980s. And so it was absolutely fascinating to me to find that a 1945 German submarine had rubber coating on its haul.

WHITECan I interject that the...

NNAMDIPlease do.

WHITE...The U-1105 actually is off Piney Point in the Potomac and it is open to diving seasonally. And I am actually very good about deploying and retrieving our mooring buoy. At the mouth of the Patuxent, there is the S-49, which is an American ship, very deep. You can dive on it. It's still -- these are both Navy property. And they are -- they don't encourage necessarily the S-49 because it is much deeper than the 1105. The 1105 is interpreted at the Piney Point Maritime Museum and open in public.

NNAMDIAnd, Don, thank you very much for your call. Susan Langley is Underwater Archaeologist for the State of Maryland. Bill Toti is project manager for the Institute of Maritime History's Mt. Vernon underwater archaeology project. And Esther White is director of archaeology at Mt. Vernon. Thank you all for joining us. And thank you all for listening. I'm Kojo Nnamdi.