"Nereide" carried 100 specially selected soldiers from the 69th and 33rd Regiments and some artillerymen from the garrison at Madras, to be used in storming and garrisoning offshore islands, beginning with Île de la Passe off Grand Port, a well defended islet that protected a natural harbour on the southeastern shore.These fortified islands could be used to block entry to the ports of Isle de France and thus trap Hamelin's squadron.