#TheRiddleOfTheSands (1979)

In 1901, two British yachtsmen visiting Germany's Frisian Islands accidentally discover a German plot to invade England.
#SpyMovies #FilmMastodon

@hms_speedy

May I also commend, as additions to your itinerary,

* #CSForester 's #HoratioHornblower
* #ArthurRansome 's #SwallowsandAmazons (and Racundra's First Cruise, which is not fiction)
* #ErskineChilders 's #TheRiddleOfTheSands