Autopsy Report of the Wreck

illustration by Tiina Miettinen

The Vrouw Maria lies at a depth of 41 meters below the waves of the Northern Baltic Sea.1 It rests upright on its keel with its bow facing South-Southwest at 156 degrees.2 Most of its impressive 26 meter by 7 meter frame remains in excellent condition considering the two-and-a-half centuries it has been submerged. This suggests its descent to the sea floor was gentle as opposed to a more violent capsizing.3

The Vrouw Maria, or Lady Mary, was a snow-rigged ship, Meaning it has an additional small mast and sail located behind the main mast.4 This style of ship building, as opposed to regular brigs, allowed the boat to have both large square sails (ideal for catching wind from behind) and smaller gaff sails (triangular sails that are ideal for catching wind from the side and for steering). However only the two main masts remain intact in their original steps, each reaching upward to depths of 22 and 24 meters respectively. The upper rigging of the masts is absent however, likely lost during the salvage attempt. The sails too have fared no better, likely being unable to withstand hundreds of years of decay on the sea floor. The hull remains intact for the most part, with no major collapses or fragmentation. The Carvel-built oak planking remains tightly fitted without signs of warping. All the main hatches remain open, allowing for some minimal water flow to the cargo hold. The rest of the weather deck displays some sporadic loss of planks but remains mostly sound. Due to the impact, prior to sinking, the rudder was fully detached and is not present by the wreck. The decorative rose-cut stern piece is also detached but parts of it have been located.5

Lempiäinen-Avci, M., Timonen, T., Harju, P., & Alvik, R. (2022). Underwater archaeobotany: Plant and wood analyses from the Vrouw Maria

The cargo remains densely packed especially in the upper areas of the cargo hold. This poses a significant risk of damaging the cargo if a diver were to make a recovery attempt. The remaining cargo that was not salvaged consists of large amounts of zinc, large quantities of porcelain, several boxes containing indigo, large quantities of coffee beans and tobacco leaves, boxes of fruit (many of which still have intact flesh and skins), and wood products used for textile production. There is also the collection of 18th-century Dutch paintings.6

“Scour pits” are large depressions in the sea floor caused by currents and water turbulence. To the southwest of the wreck (down stream), an enormous scour pit stretches 150 by 300 meters. This is caused by the diversion of currents around the hull of the Vrouw Maria.7 Sedimentation remains remarkably low, only the bottom most meter of the hull sits beneath the anaerobic mud, the rest of the wreck is entirely exposed. Thanks to the low salinity of the Baltic sea, there is no evidence whatsoever of shipworms eating away at the wood. However, after the ship received critical damage from a reef, it has ironically become an artificial reef of its own, providing shelter and housing for clams and worms alike.8 Thankfully, neither of these species pose any threat to the integrity of the vessel. However, a slight whitish grey biofilm has formed over much of the cargo, suggesting slow bacterial degradation. Stable temperatures ranging from -0.4 to 8 degrees Celsius, also aid the prevention of weathering. 

anchor of the Vrouw Maria

The greatest threats currently posed to the structure of the wreck, ignoring the initial blunt trauma and the ensuing stress from drifting in a storm for several days, seem to be minimal. There are detectable amounts of microscopic soft rot which affects the cell walls of the wood.9 This combined with the somewhat strong currents, amounts to the extent of the erosion that the ship is exposed to. Perhaps the greatest issue is the risk that the intact masts pose. They can effectively work as levers and, with any amount of turbulence or vibration from the ocean currents, can directly transmit mechanical stress to the deck and hull which would risk exposing the cargo hold.10

Overall the wreck seems to be in a steady state of slow degradation. While the lack of shipworms ensures structural longevity, the chemical fragility of the waterlogged wood and the mechanical stress from currents mean the site is highly sensitive to any physical disturbance or climatic shifts in water temperature.

  1. Ruuskanen, A. T., Kraufvelin, P., Alvik, R., Díaz, E. R., Honkonen, J., Kanerva, J., Karell, K., Kekäläinen, P., Lappalainen, J., Mikkola, R., Mustasaari, T., Nappu, N., Nieminen, A., Roininen, J., & Svahnbäck, K. (2015). Benthic conditions around a historic shipwreck: Vrouw Maria (1771) in the northern Baltic proper. Continental Shelf Research, 98, 1–12. ↩︎
  2. Leino, M., Ruuskanen, A. T., Flinkman, J., Kaasinen, J., Klemelä, U. E., Hietala, R., & Nappu, N. (2011). The natural environment of the shipwreck Vrouw Maria (1771) in the Northern Baltic Sea: An assessment of her state of preservation. International Journal of Nautical Archaeology, 40(1), 133–150. ↩︎
  3. Lempiäinen-Avci, M., Timonen, T., Harju, P., & Alvik, R. (2022). Underwater archaeobotany: Plant and wood analyses from the Vrouw Maria, a 1771 shipwreck in the Finnish Baltic Sea. Vegetation History and Archaeobotany, 31, 97–106. ↩︎
  4. Leino, M., Ruuskanen, A. T., Flinkman, J., Kaasinen, J., Klemelä, U. E., Hietala, R., & Nappu, N. Natural environment of the Vrouw Maria ↩︎
  5. Leino, M., Ruuskanen, A. T., Flinkman, J., Kaasinen, J., Klemelä, U. E., Hietala, R., & Nappu, N. Natural environment of the Vrouw Maria ↩︎
  6. Lempiäinen-Avci, M., Timonen, T., Harju, P., & Alvik, R. Plant and wood analyses from the Vrouw Maria. ↩︎
  7. Ruuskanen, A. T., Kraufvelin, P., Alvik, R., Díaz, E. R., Honkonen, J., Kanerva, J., Karell, K., Kekäläinen, P., Lappalainen, J., Mikkola, R., Mustasaari, T., Nappu, N., Nieminen, A., Roininen, J., & Svahnbäck, K. Benthic conditions around Vrouw Maria. ↩︎
  8. Ruuskanen, A. T., Kraufvelin, P., Alvik, R., Díaz, E. R., Honkonen, J., Kanerva, J., Karell, K., Kekäläinen, P., Lappalainen, J., Mikkola, R., Mustasaari, T., Nappu, N., Nieminen, A., Roininen, J., & Svahnbäck, K. Benthic conditions around Vrouw Maria ↩︎
  9. Gril, J. (Ed.). (2010). Wood science for conservation of cultural heritage – Braga 2008: Proceedings of the International Conference held by COST Action IE0601. Firenze University Press. ISBN 978-88-6453-157-1. ↩︎
  10. Ruuskanen, A. T., Kraufvelin, P., Alvik, R., Díaz, E. R., Honkonen, J., Kanerva, J., Karell, K., Kekäläinen, P., Lappalainen, J., Mikkola, R., Mustasaari, T., Nappu, N., Nieminen, A., Roininen, J., & Svahnbäck, K. Benthic conditions around Vrouw Maria ↩︎