Description Originally a shipping company, Siem Offshore has become a major player in the oil field services industry. It has a fleet of 27 vessels, including platform supply vessels (PSVs), multipurpose field- and remotely operated vehicle (ROV) support vessels, multi-role support vessels (MRSVs), anchor handling tug support vessels, a well stimulation vessel, a scientific core drilling vessel and crew boats. The company also conducts technology research and development for the drilling and well services industries through Siem WIS AS and WellCem AS. Norwegian shipping conglomerate Siem Industries owns about 34% of Siem Offshore.