Abstract: A vessel for use in the production and/or storage of hydrocarbons, including a receiving device having a downwardly open space for receiving and releasably securing a submerged buoy connected to at least one riser, a rotatable connector for connection with the buoy and transfer of fluids, and a dynamic positioning system for keeping the vessel at a desired position. The vessel includes a moonpool extending through the hull, and the receiving device is a unit which is arranged in the moonpool for raising and lowering, the rotatable connector being arranged at deck level, for connection to the buoy when the receiving unit with the buoy has been raised to an upper position in the moonpool.