 In August 1810, a squadron of four of Rowley's frigates, making up the majority of the forces under his command and led by Captain Samuel Pym, were despatched to Île de France to blockade Grand Port on the south-eastern coast.The arrival of a French squadron under Captain Guy-Victor Duperré on 20 August prompted Pym into ordering an inadequately planned attack on the harbour on 23 August and two of his vessels were wrecked on the reefs that protected the harbour entrance.Pym was unable to withdraw his remaining ships and the entire squadron was lost, leaving Rowley with only his flagship HMS "Boadicea" and two small brigs to conduct his campaign against six large French frigates.