The Baltic Sea is a graveyard of ships that have sunk over the past few centuries, in particular the two World Wars. German maritime expert Thomas Dehling has an eye on shipwrecks and sunken objects - and their exact positions. 
 
 DW: How many shipwrecked boats are there in the Baltic Sea? 
 
 Thomas Dehling: I don't know the figure for the entire Baltic Sea, but in German waters - about 16,000 square kilometers (6000 square miles), less than a tenth of the Baltic Sea - there are quite a lot, roughly 1,000 objects that we know about. 
 
 In the Baltic Sea, we have quite a lot of shipwrecks due to the two World Wars, more than in other seas. Most of the objects are from the early 20th century, but there is one shipwreck in Finnish waters that is more than 400 years old. In our part of the Baltic, there's an old wooden shipwreck that dates to the 15th or 16th century, the archeologists aren't sure. There's not much left but the cargo was still there: copper disks, a really unusual find so far north. 
 
 We regularly survey the objects, especially those that are potentially dangerous to shipping, depending on the importance of the object and the sea lane, maybe once a year or only once every 25 years. 
 
 How unusual would a 
 
 off the Swedish coast be? 
 
 There are several WWII Russian submarine shipwrecks in the Baltic Sea, that isn't unusual. In the case of the shipwreck off the Swedish coast, it depends on how old it is. Because of the wars, there are English submarines in German waters in the North Sea, a Polish shipwreck in the Baltic Sea, a German shipwreck in Polish waters. If the Russian submarine is not that old, it is obvious that a Russian submarine entered Swedish waters clandestinely. 
 
 Is the Baltic Sea popular with recreational divers? 
 
 Yes it is - and it's dangerous. Very often fishing nets get caught in the objects and you have to be very experienced to dive there. That's why we don't disseminate our information on the shipwrecks. 
 
 But there's a map on your website? 
 
 Yes, but you won't find an object when you use that map because it's not that precise. Of course we have to inform the maritime community about obstructions that might hinder their traffic, but we don't inform the public about objects that might be of historic interest - only people who can claim that they need to have the information. 
 
 Have you charted all of the objects in your sector by now, or do you still find new ones? 
 
 In our part of the Baltic Sea, we still find 10 to 15 objects every year that we didn't know about before, thanks to the modern technology on our ships that lets us survey the seafloor in much more detail. And many of the objects aren't large shipwrecks, but much smaller, or partially submerged. And they're not the ones that are potentially dangerous to shipping, we know about those. We don't remove anything, we inform the water and shipping administration, and it's up to them to decide whether to remove an object or set up a buoy. 
 
 Thomas Dehling heads the hydrographic surveying division at Germany's Federal Maritime and Hydrographic Agency (BSH), which provides maritime service for the shipping. The agency is based in Hamburg and Rostock. ||||| The term “vintage” may now have a whole new meaning for wine lovers—a treasure trove of 170-year-old champagne has been unearthed from the bottom of the sea. In 2010, a group of divers in the Baltic Sea happened upon the remains of a sunken trade schooner just off the coast of Finland. Scattered amongst the wreckage 160 feet below the surface, they discovered a treasure sent from Dionysus himself—168 bottles of French bubbly that had aged in near perfect conditions for decades. 
 
 Although the local government ultimately claimed the bottles, a team of scientists led by Philippe Jeandet, a professor of food biochemistry at the University of Reims, was able to obtain a small sample of the preserved beverage for testing—and tasting. Their chemical and sensory analysis, published today in the Proceedings of the National Academy of Sciences, provides a unique lens into the past, offering information about conventional winemaking practices in the 19th century as well as the likely destination of the lost trade ship. 
 
 Despite the fact that the labels had long since worn off, branded images on the interior surface of the corks allowed the team to identify the original vintners. Several champagne houses were represented, including Veuve Clicquot Ponsardin, a well-known brand founded in 1772 that still exists today. To conduct their chemical analysis, the team compared the older “Baltic wine” with modern Veuve Clicquot. Their results show that the Baltic versions contained lower alcohol content and higher sugar levels than their modern-day counterpart. 
 
 Many of these chemical differences can be explained by “steps in the production process that were less controlled than they are today,” says Jeandet. Specifically, the researchers believe that the lower alcohol levels are a consequence of a colder average climate, which would inhibit grape maturation and overall levels of alcohol from sugar, as well as use of a less efficient yeast product. Also, while individual grapes did not produce particularly high sugar yields, 19th-century winemakers were known to add a considerable amount of sugar to artificially sweeten their champagnes. Addition of sugar syrup at the end of the production process would have diluted the wine, also possibly accounting for the lower alcohol content. 
 
 “Today most champagnes contain low levels of sugar that are added at the end of the process,” says Jeandet. “The Baltic wine we analyzed contained at least 140 grams of sugar per liter, as compared to about 6 to 8 grams per liter used today.” 
 
 The aged wine also had enhanced levels of iron, copper, sodium and chlorine. The researchers hypothesize that the increased concentration of iron and copper, accompanied by several wood compounds, suggests the use of metal- and wood-containing vessels during the manufacturing process. This contrasts with the steel vessels that are predominately used today. Furthermore, in the 1800s “copper sulfate was often used for the control of disease in the vineyard, as opposed to fungicide containing organic compounds used today,” says Jeandet. This also accounts for the high levels of copper compounds observed. 
 
 Meanwhile, the heightened levels of sodium and chlorine in the Baltic wine can be attributed to salt, which was repeatedly added to help stabilize wine during the 19th-century manufacturing process. Today, these similar processes occur after the blending of the wine, leading to relatively lower sodium levels. 
 
 According to the authors, the sugar content also provides an important clue about the destination of the trade schooner. The location of the wreckage suggests that the ship may have been destined for a Russian market. However, historical records of regional preferences in wine sweetness provide conflicting evidence. The Russians demanded extremely high sugar levels of around 300 grams per liter. Russians had such a sweet tooth that “it was common to have sugar on every table close to the wine glass—for they added sugar not only to red wine, but also to champagne,” says Jeandet. This spurred the creation of an entirely separate brand of extra-sweet bubbly called Champagne à la Russe. 
 
 The Germans and French, meanwhile, demanded more moderate sugar levels of approximately 150 grams per liter, while British and American connoisseurs preferred even lower levels of around 20 to 60 grams per liter. Based on the measured sugar content of the Baltic wine, the authors think this particular shipment was probably destined for the Germanic Confederation, whose constituents preferred more moderately sweetened champagne. 
 
 So what about the question that virtually everyone is asking: “What does this stuff taste like?” 
 
 By a stroke of luck, most of the bottles had been preserved in ideal conditions—at a depth characterized by minimal light and temperatures ranging between 35 and 39 degrees Fahrenheit. The researchers observed very low levels of acetic acid in the wine, a primary red flag for spoilage. So as part of the testing, the team had a panel of wine experts take a taste. The compiled responses were then compared to the chemical findings. 
 
 Initially, the experts described the Baltic wines with words such as “animal notes,” “wet hair” and “cheesy.” However, after the wine was swirled a bit in the glass, providing some much needed oxygen, it took on a whole new character. Once it had a chance to breathe, the champagne was described as “grilled, spicy, smoky, and leathery” accompanied by fruity and floral notes, according to the paper. 
 
 Although he was not given a bottle to keep for himself, Jeandet was able to obtain a small personal sample of 100 microliters to try. “It was incredible. I have never tasted such a wine in my life,” says Jeandet. “The aroma stayed in my mouth for three or four hours after tasting it.” Wine connoisseurs seem to agree, as several of these bottles have been auctioned off for up to 100,000 euros each, according to Jeandet. Other bottles have been sent to museums or historical institutions. Further work may prove useful to enologists who are now investigating the potential for deep-sea aging as a technique to enhance or augment the taste of various wines.
– The Baltic Sea's trove of shipwrecks has preserved all kinds of history—much of it about war—and recently sparked fears of a fresh conflict in Europe. Bordered by Scandinavia, Finland, the Baltics, the North European Plain, and accessible by Russia, one sliver of the sea contains about 1,000 known shipwreck objects, maritime expert Thomas Dehling tells Deutsche Welle. He's referring to what slumbers in 6,000-square-miles of "German waters," which he says represent not even a tenth of the full sea. "Many of the objects aren't large shipwrecks, but much smaller, or partially submerged [ones]," he says. "We still find 10 to 15 objects every year that we didn't know about before." Most are from World War I and II, but not all: A Swedish three-masted warship called the Mars went down in 1564 while battling the Danes and may have been cursed by its own cannons, National Geographic reported last year. Discovered in 2011, the warship sank when its cannons overheated and exploded during battle; legend says it was cursed because Swedish kings repurposed church bells to build the cannons. In another Baltic find, 168 bottles of perfectly preserved 19th-century French champagne were discovered on a sunken schooner near Finland, Smithsonian reports. "It was incredible," says a scientist of the bubbly that later sold for up to $100,000 a bottle. Then last year, Sweden saw its Cold War fears revived—and concerns about modern Russia heightened—when said it spotted a foreign sub in its waters. Sweden now says a Russian sub may have indeed been found in the Baltic ... but the wreckage is thought to be that of a WWI vessel that likely went down almost 100 years ago. (Read about a "sickening" shipwreck find in the Arctic.)