A production support and storage vessel is provided, as well as a method of processing material, such as ore, gathered from the seafloor using such a vessel. The production support and storage vessel has facilities to receive ore from the seafloor, process it, and store the ore in bulk storage silos. Additionally, the production support and storage vessel has a ballast capability and system to ballast the vessel down to a full operational draft. When needed, typically approximately weekly, a transport vessel is moored to the production support and storage vessel and the production support and storage vessel offloads the stored ore using a conveyor system.