The OOS Walcheren is the 3rd vessel using the asymmetric brace-less semi-submersible design within the OOS family. The first is the OOS Gretha, currently operating in Brazil, and the 2nd is the OOS Serooskerke, which is under construction and due for delivery in Q3 2019. A total of 28 sub blocks are being keel layed. The weight of each