CIMC Gretha，Semi Submersible Crane& Accommodation Vessel, Main deck crane 2 x 1800Tons. As the owner Ocean Challenger got involved in the later stage supervision management for the vessel in March 2012. The sea trial began in 14^th August 2012. Yantai CIMC Raffles delivered it to OC on 18^th December 2012. After that OC assisted shipyard to complete the modification as requirements. CIMC Gretha delivered on 25^th November 2013 at last and reached in Brazil on 9^th March 2014. 18^th April 2014, it succeeded to pass the inspection by Petro Bras and started to work in Brazilian water.