the royal navy purchased her in early 1803 and deployed her under the command of acting lieutenant charles robbins to assist surveyor charles grimes in mapping the coastline of king island and port phillip. on her return to port jackson, she was assigned to convey matthew flinders to england. however the poor condition of the vessel forced flinders to put into french-controlled mauritius, where he and the ship were interned. "cumberland" remained in mauritius when flinders was released on 13 june 1810. flinders left on the cartel "harriet", bound for bengal, but when she encountered , he transferred to her as she was carrying dispatches to the cape.