ship when he was aged 12. His experience of seafaring only confirmed his interest in a career at sea, so in March 1800, Franklin's father secured him a Royal Navy appointment on .

Commanded by Captain Lawford, the Polyphemus carried 64 guns and, at the time of Franklin's appointment, was still at sea. He did not join the vessel until the autumn of 1800. Initially serving as a first-class volunteer, Franklin soon saw action in the Battle of Copenhagen