Rock Solid Images plc (RSI), formerly Offshore Hydrocarbon Mapping plc, is a geophysical services company. The principal activity of its main operating subsidiary, Rock Solid Images Inc., is to use controlled source electromagnetic, well log and seismic data to enhance oil and gas exploration and exploitation activities. RSI operates in three segments: Well-driven Integration of Seismic and Electromagnetics (WISE) business and the Well and Surface Seismic (WSS) business. It provides a range of solutions, which include sub-basalt imaging, deep water turbidites, reservoir properties, facies models, reservoir appraisal, gas saturation determination, fractured reservoirs, carbonate reservoirs, unconventional reservoirs and 4D (time lapse). On November 2, 2010, the Company completed the disposal of its marine Controlled Source Electromagnetic (CSEM) acquisition businesses, OHM Limited and OHM Surveys Sdn Bhd.