Description Oostvoornse Meer
The Oostvoornse Meer is a lake created in the 1960's, when the mouth of the Meuse near Briel was closed. It once was a busy shipping route and most sites are 17th century shipwrecks. The wrecks are probably a result of a shallow sandbank called "De Hondenplaat" and the ships will have sunk rapidly due to the tides and river streams.
After the closing of the Oostvoornse Meer, sand excavations begun for the construction of Maasvlakte 1 and shipwrecks were revealed. Because the Oostvoornse Meer is situated at the estuary of the Meuse, a thick layer of silt was present. The sediment had highly preserved the remains and the sand excavation exposed and disturbed many wrecks. Because of the exposure of the wrecks, they were now vulnerable to illegal excavations and natural threats, like the shipworm Teredo navalis. In the Oostvoornse Meer more than a dozen of shipwrecks are known, many of which are affected by the shipworm.
The Oostvoornse Meer 12
During a research campaign by the Rijksdienst voor het Cultureel Erfgoed (Cultural Heritage Agency of the Netherlands) in 2014, an inspection dive was made to the OVM12. The wreck lies at 35 to 40 meters depth, were the water temperature is much lower, 8 degrees Celsius, than at the lakes surface, were it's 18 degrees Celsius.
The inspection showed a large seafaring ship, with at least two decks and a possible third (half)deck. The hull is made of multiple layers and the ship is reinforced at board and deck. These reinforcements suggest the ship was heavily armed with cannons and was probably in use as a warship. On deck a large amount of rope and pieces of leather are present. One wood sample of the ship was taken for dendrochronological research and was dated to 1605.
The Oostvoornse Meer 12 (OVM12) is a large wooden seafaring ship, dating to the 17th century. The ship has at least two decks and a possible third (half)deck. The hull has multiple layers and the reinforcements of the ships board and deck suggest the ship was once heavily armed with canons. It is possible the OVM12 was a warship.
The diving inspection in 2014 showed the wreck was not, or barely, affected by the shipworm, Teredo navalis. It had no signs of attacks by shipworms in the past and present. This makes the OVM12 the only wreck in the Oostvoornse Meer that has not been affected by the marine borers. The one wood sample confirms this. The ropes and pieces of leather are also in very good condition.
Although the wreck is in good condition now, it is probably only a matter of time until the wreck will be affected by the shipworm. The salinity, temperature and oxygen level in the lake are perfect for shipworms, only the temperature in deeper areas is too low for the shipworm to become a threat. A change of the salinity of the water can be a solution for preventing the shipworm to affect the OVM12 and other shipwrecks in the Oostvoornse Meer.
In June 2015 the Cultural Heritage Agency of the Netherlands (RCE) will start a campaign to determine the quality of the wreck and to value the site. The possibilities to protect the wreck and the possibilities to open the site for sports divers will be researched. A detailed site plan will be made with 3D techniques.
The results of the campaign will be used to give an selection advice for the OVM12, which can be used for the protection of the wreck site.