 The success allowed British forces to concentrate against the one remaining French territory in the Indian Ocean , Isle de France . Bourbon provided a number of secure anchorages and plentiful supplies for the British frigate squadron , becoming Rowley and Keating 's new headquarters . With a safe harbour only a short journey away , Rowley was able to despatch his frigates against French ports on Isle de France more frequently and more aggressively , developing a plan to seize small offshore islands near the main harbours on Isle de France to disrupt the passage of shipping and the ability of French frigates to use these ports as raiding bases . This plan ultimately led to the disastrous attempt to seize the shipping in Grand Port in which four frigates of Rowley 's squadron were lost . 
