The Bronze Age logboat from the Eschbach Bay next to Wasserburg in Lake Constance - the oldest boat in Bavaria

In 2015 Christoph Schmid reported a logboat find in Lake Constance near Wasserburg. Christian Schaber (Lindau Water Rescue Service) then produced the first film and photo material. In autumn 2015, the Bavarian State Office for the Preservation of Monuments (BLfD) was informed, which in turn commissioned the BGfU to document the underwater discovery. In November 2016 Tobias Pflederer, Robert Angermayr and Detlef Peukert carried out the investigations. The BGfU divers received financial support from the BLfD's department "Volunteer work in the preservation of ground monuments".

Despite adverse weather conditions with strong winds and high waves, the watercraft could be rediscovered on the first working day at a distance of approx. 170 m from the shore. The site is located near the mouth of the Eschbach (a small river) at a water depth of approx. 3 to 4 m. Franz Herzig, dendrochronologist at the BLfD, was able to examine two radial samples taken with a wood drill on the same day. He succeeded in reconstructing a 97-year-old oak series, which, however, initially did not permit a clear dating.

After the wood sampling, the inner body of the logboat was cleaned, which was only covered by a thin and recent layer of silt. The subsequent documentation was based on a photo documentation with subsequent 3D reconstruction and calculation of a true-to-scale photo mosaic. The wood has broken out in the presumed bow area and has a residual length of 6.80 m with a maximum width of 1.05 m. It lies in southwestern orientation to the current course of the shore. Due to the lack of sediments under the sharp-edged bow area and the almost complete lack of sediment cover, relocation or alluvial deposit to the current location appears possible. The wall rising from the relatively flat floor is almost completely eroded. In the largely well preserved, presumed rear area, the rest of a rectangular, vertical recess ("nose") is visible. The question as to whether this had originally been used for mooring on land cannot be answered clearly. Another special feature is a small, approx. 7 x 5 cm gap towards the rear, which completely penetrates the wood at this point. Their function must also remain unclear at first. Small-bore test drillings are known from other logboats, through which the thickness of the logboat was checked during the production process. Another conceivable option is a recess element for inserting smaller installations.

A special surprise was the radiometric analysis a few weeks after the underwater archaeological documentation. The logboat dates back to the late Bronze Age. By taking another wood sample in 2017, Franz Herzig from the dendrochronological laboratory of the BLfD then succeeded in dating it to the year 1149 B.C. (as the edge of the trunk is missing, it can be assumed that the tree used was felled around 1130 B.C.).

This makes the logboat the "oldest boat" in Bavaria to date and the only real logboat of Lake Constance (apart from two "toy" logboats from Sipplingen and Arbon and the report of another logboat from the 1930s near Konstanz-Wollmartingen).

Due to the historical significance of the logboat, the Bavarian State Office for the Preservation of Monuments and the Munich State Archaeological Collection decided to recover and conserve the watercraft. The employees of the BGfU, who carried out the rescue in April 2018 in four days, were again commissioned with the task. The divers of the BGfU again received active support from the Lindau Water Rescue Service and the Kempten Water Management Authority.

In two and a half days, the logboat was first freed of sediment adhering to the ground using underwater dredges (with the exception of glacial sediments and a reduction layer of baked gravel, there were no indications of cultural layers under the logboat). In a next step, several belts with padding were placed under the logboat and installed on a salvage frame specially made by the State Archaeological Collection. By gently pulling the underlaid straps, the logboat could be gradually pulled to the upper edge of the frame. After the logboat swam free, the salvage frame and the logboat were lifted by a salvage-crane-vessel and loaded onto a low-loading truck in the port of Zech. After more than 3100 years the logboat of Wasserburg started its last journey. Preservation will now take at least two to three years.

Tobias Pflederer, Robert Angermayr