He made the one-off trip after nine-year-old pupil Beatrice Delap wrote to the star asking for help staging a ‘mutiny’ against the teachers, as he was filming at the nearby 18th century Old Naval College.
The school was told just ten minutes before that Depp would be arriving and two blacked-out cars swept through the school gates.
An onlooker said she heard the most ‘incredible screams of joy’ as the actor, in full make-up, then entered the school.
A teacher was smart enough to whip out her cell phone and take a quick video of the event.
By the way, how cool is Johnny Depp?