History on the Seabed

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Water covers more than two-thirds of the surface of our planet. The Baltic with all its bays and inlets is only a small drop in that ocean, but for marine archaeologists and divers it is a fascinating and rewarding place. Systematic exploration of the treasures that it holds is only now beginning as new methods are adopted. Finnish researchers cannot hide their enthusiasm.

Most of the oceans are kilometres deep, with some trenches in the Pacific plunging to depths in excess of ten thousand metres. The Baltic, by contrast, has an average depth of only 55 metres. In fact, it is one of the smallest, shallowest, most island-dotted and shoaliest seas in the world.

For as long as the seas have been sailed, hundreds of vessels that have strayed off course or lost their battles with storms have ended up at the bottom of the Baltic, especially in its countless bays and inlets. Floor plates believed to have belonged to a Viking ship have been found in the Gulf of Finland. As research methods become more systematic, much more is likely to be uncovered.

The Roman historian Tacitus reported nearly two millennia ago that the Germans obtained the furs they valued so highly "from beyond the unknown sea", i.e. the Baltic. The Vikings' eastward expeditions took them through the Gulf of Finland and on to Lake Ladoga. Over the centuries, fierce sea battles have been fought for control of that vital trade artery the Baltic. One indication of its continuing importance is that bristles with air and naval bases. Small wonder, therefore, that the waters of the archipelagos fringing the Finnish coast contain so many relics of history waiting for researchers to find them - if only they can.

No devouring worms, but crushing ice

The Baltic is the world's biggest body of brackish water; its salinity varies from almost nothing to 1.5 per cent, compared with an average of 3.4 per cent in the oceans. Maija Fast of the Finnish Maritime Museum sees the Baltic as a paradise for marine archaeologists: "It's really an exceptional inland sea. The low salinity means that the wood-eating shipworms common in the oceans do not thrive here. Wooden wrecks are very well-preserved. It is different elsewhere; for example, we are collaborating with Australian scientists to study the wreck of a Finnish ship that went down north of Kangaroo Island in 1860 and is now a protected archaeological site. All that remains of it is a collection of glass, pottery and metal objects; the worms have completely devoured the wooden hull. That would not happen in the Baltic".

Image size 19 Kb Maija Fast and the lightship Kemi (built 1909) at the Maritime Museum, which is on the tiny island of Hylkysaari just off Helsinki.



"On the other hand, ice can be a mighty destructive force. When it begins breaking up in spring, formations of pack ice can reach as far as twenty metres below the surface of the sea and crush all beneath them. And naturally, the incessantly moving sea shifts everything lying on its bed. If a wreck lies beneath the channels that large vessels ply, it can likewise suffer damage. For example, a warship sunk off Kotka during the Battle of Ruotsinsalmi in 1790 happens to lie below a turn in the channel, a place where ships' propellers are revved up. Since the water there is fairly shallow, strong currents buffet the wreck."

New sonar never fails

Side-scanning sonar is one of the latest technological tools that enable the sea floor to be searched systematically. In the past, most wrecks were found by chance. Cartographers from the Board of Navigation often found them, and some are even marked on sea charts. The Navy has also found a good few, as have amateur divers.

"Side-scanning sonar produces a three-dimensional image of the sea floor, whereas all that ordinary sonar gives you is a profile," explains Maija fast. "The image is nothing like a photograph; in fact, an untrained person cannot even read it. When scans are done in shallow water from slow-moving vessels, the minutest details of objects are revealed, and even at high speed in deep water wrecks show up clearly. This kind of sonar also detects wood, not just metal. Even if a dozen divers comb the sea floor, they are really looking for a needle in a haystack. On the other hand, side-scanning sonar can search a large area in a short time. Now, for example, there is a very real possibility that, say, the entire Gulf of Finland can be charted in the detail that marine archaeologists would like it to be."

The Board of Navigation and the Navy have side-scanning sonar, but the Maritime Museum does not. That problem has now been partly overcome, because a private company has purchased equipment and rents it, together with operatives skilled in its use, to researchers and amateurs. Diving clubs have been quick to avail of the new service and in summer 1997 found two wrecks.

"We at the Maritime Museum are hoping the new sonar will help us find something like a Hanseatic cog, a type of merchant vessel used in the Baltic during the Middle Ages. We know that some of them were shipwrecked in Finnish waters. So far, only two 16th-century wrecks have been dated. The older a wreck is, the more interesting. It was only in the 18th century that drawings of vessels began to be made on a systematic basis. Wrecks are the only older 'documentary records' of naval architecture and life on board ships," says Maija Fast.

The Czarina's carriage at the bottom of the sea

Wrecks can lie kilometres below the surface in the oceans, but most of those that have been studied in Finnish waters are at depths of only 10 - 20 metres. Only experienced divers can venture below 30 metres, and historically interesting wrecks lying at greater depths have been discovered by chance rather than design. Image size 5 Kb

This Jacob's staff was found in a sea chest recovered from the wreck of the St. Mikael in 1986. The staff, a precursor of the sextant, was used to determine the ship's position with the aid of the stars.

One of the most interesting research sites off the Finnish coast is 40 metres below the waves. It is the Russian merchant ship St. Michael, which foundered near Börstö off south-west Finland in autumn 1747 while en route from Amsterdam to St. Petersburg. Some of the cargo was washed up on the shore and auctioned in Turku the following year. Divers have been studying the wreck, under the supervision of the Maritime Museum, for the past nearly forty summers. Among the objects that they have found are a rococo carriage made for the Czarina Elisabeth Petrovna, extraordinarily beautiful tableware and other valuables. Several other important, if lesser-known, wrecks are likewise being studied on a continuing basis. Experts expect that side-scanning sonar will enable new completely preserved wrecks to be found at depths of 40 - 50 metres over the next few years.

"If anyone finds even a single rib of an old ship on the sea floor, it must be reported to the museum authorities at once," Maija Fast points out. "The first rule to remember is that the object should be kept moist; if it is allowed to dry, it will crumble. Conservation is done in several stages. First the piece is kept in fresh water to leach out the salt. Then the water, which has filled the cells of the wood for so long, is replaced with a plastic solution. If the piece is large, this can take a few years. Before this procedure was introduced, conservation attempts proved fairly futile. The huge Swedish warship Wasa, which sank on its maiden voyage and is now on display in Stockholm, was sprayed with a plastic solution for nearly twenty years after it was salvaged."

Amateur divers helping researchers

Image size 6 Kb There are about 20,000 amateur divers in Finland and foreign guests are welcome to join them in the depths. Clubs organise diving trips for visitors, and permits to visit wrecks can be obtained. Visitors should, however, bear in mind that the water in this part of the world is a good deal colder than in the tropics and visibility can be poor. By law, wrecks over 100 years old - counted from the date of sinking - are preserved sites that may not be interfered with without official permission.

A lot of damage has resulted from careless anchoring. It does not take much imagination to picture what happens to a brittle wreck when a heavy anchor hits it. The National Board of Antiquities is the supervisory authority and is assisted in its work by the Coast Guard.

Says Maija Fast: "Amateur divers are a great help to the Maritime Museum. Dozens of permits to study wrecks are granted each year. Divers measure, photograph and video wrecks and hand in articles that they find. They have put a lot of effort into acquiring certain skills and get more out of their pastime when they know that they are doing something useful."

Bubbly on the Seabed

A good deal younger than the St. Michael, but no less interesting, is the wreck of the schooner Jönköping. The wooden two-master was built in Sweden in 1896 and sailed the seas for two decades before a torpedo from a German submarine sent her to the bottom of the Baltic off the Finnish city of Rauma in 1916.

The Jönköping was carrying a cargo of 5,000 bottles of champagne and 67 barrels of cognac and wine destined to be consumed by officers of the Imperial Russian army. Small wonder that when the wreck was discovered some time ago its cargo - now estimated to be worth at least $1 million - quickly attracted several rival teams of divers. The bubbly in the few bottles that had been brought to the surface proved to be of excellent quality and so it was only a matter of waiting for the right weather to enable the whole vessel to be raised.

That was accomplished in July 1998 when a Swedish salvage team arrived with a floating crane and hauled the wreck to just below the surface, where it remained for several hours while the cargo was retrieved.

The champagne was fine and will fetch a lot of money, but the wooden barrels were more than a disappointment. They proved to contain a foul-smelling cocktail of wine or brandy and brackish Baltic water.

Art Treasures for the Empress

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A wreck discovered by Finnish divers in late June 1999 with the aid of advanced sonar equipment is very promising. It is the Dutch ship "Vrouw Maria", lying in 41 metres of water between the islands of Jurmo und Borstö off the west coast, not far from where the St. Mikael was found.

The Vrouw Maria was on her way from Amsterdam to St. Petersburg when she ran aground on 3 October 1771. Her cargo contained art treasures ordered by Catherine the Great. The divers found a wreck full of wooden crates, but what they contain will remain a mystery until some time in the year 2000 at the earliest. That is because the funds that would have been needed for a proper examination of the unexpected find were not available. Now, however, Culture Minister Suvi Lindén has promised that an appropriation will be included in the next budget.

See also:
WTF-O The treasure ship's 230-year slumber
Wrecks in Finland