The Indefatigable was a ship with the British Royal Navy that, according to Lord Admiral Horatio Nelson, was lost at the Nile, prior to the Battle of Trafalgar in 1805.
When questioned about his last ship, Ben Jackson claimed that before being a member of the TARDIS, he was with the Indefatigable. (PROSE: H.M.S. TARDIS)
Behind the scenes Edit
This is a reference to the Battle of the Nile in 1798. No ship by this name took part in the battle in the real world.