John Stewart's connections into the EIC allowed William, aged 12, to join the Royal Navy as Captain William Gordon's captain's boy in November 1755, aboard HMS St Albans. This allowed the quiet but arithmetically skilled boy to be schooled further, and his ship saw action with the bombardment and capture of Louisburg (French Canada) in July 1757. In 1760 he joined the new HMS Thunderer as Midshipman officer, under Captain Charles Proby.
