The launch ceremony for the NEPTUNE took place on 23 September 2011 at the IHC Merwede shipyard in Krimpen aan den IJssel, The Netherlands. The self-elevating heavy-lift jack-up vessel is being built by IHC Merwede for GeoSea NV, the offshore marine construction specialist company within the DEME Group, based in Belgium. The contract for the detailed design, construction and delivery of the vessel was signed between GeoSea and IHC Merwede on 16 September 2010 and the keel was laid on 25 March 2011.