 Complete the following phrase:  Halsted and Namur were then assigned to Sir John Borlase Warrens squadron during the Atlantic campaign of 1806, until Namur was paid off in July 1807. In December 1807 he became Captain of the Fleet to the commander of the Lisbon station, Vice-Admiral Sir Charles Cotton, serving aboard Cottons flagship . The British fleet were engaged in blockading a Russian fleet under Admiral Dmitry Senyavin in the Tagus after the outbreak of the 