Diving support and construction vessels are mainly used as installation and maintenance ships for offshore structures. The DSV combines construction and diving tasks. Especially during dives, a DSV must remain in the exact position, which is accomplished with either multiple point anchoring or a dynamic positioning system. Equipped with diver systems for mixed gas diving and/or scuba diving, these vessels can be deployed in both coastal waters and deep sea areas. Mostly active heave compensated, the vessel cranes also support divers who undertake offshore construction tasks. On many DSVs, major equipment pieces such as diving bells, diving lifts, ROVs and hyperbaric chambers are permanent fixtures. Spacious accommodations for the crew, diving personnel and other fitters are proof of the vessel’s versatility. The ships vary significantly as to their dimensions and the scope of their capabilities.