Towards the end of the voyage, Markham experienced growing doubts about a conventional naval career; he now desired above all to be an explorer and a geographer. On arrival in Portsmouth in July 1848 he informed his father of his wish to leave the navy, but was persuaded to stay. After a brief period of service in the Mediterranean Markham experienced months of inactivity while based at Spithead and the Cove of Cork, which further diminished his interest in the service. However, early in 1850, he learned that a squadron of four ships was being assembled to undertake a new search for the lost Arctic expedition of Sir John Franklin. Markham used his family's influence to secure a place in this venture, and in April 1850, was informed of his appointment to , one of the squadron's two principal vessels.