Lord Wolfingham, the villain of this movie, is clearly based on Lord Francis Walsingham - an unhappy libel for a great patriot. Lord Walsingham was one of Queen Elizabeth's closest advisers, and would never have betrayed her.
Henry Daniell couldn't fence. The climactic duel had to be filmed using a double and skillful inter-cutting.
The role of Dona Maria was intended for Olivia de Havilland, but she was tired of being in swashbuckling movies at this time and accepted another offer, so Brenda Marshall was called on to take her place instead.
The beautifully crafted costumes seen in "The Sea Hawk" were made for Flynn’s movie from the year before called The Private Lives of Elizabeth and Essex (1939). Reusing them saved Warner Bros. a huge amount of money, since the costumes were heavily researched, meticulously created and costly in their day.
This movie is a version of Seton I. Miller's story "Beggars of the Sea," and as such is radically different from the original "Sea Hawk" novel and movie.
South African Orlando Boys Club (founded in 1937) were renamed to Orlando Pirates having been influenced by the film. Orlando Pirates are a Premier Soccer League team.
French visa # 4577.
Finnish censorship visa # 23684 delivered on 4-8-2005 (DVD)
Warner Bros. constructed a huge sound stage then known as the Maritime Stage. It had an internal tank that could be flooded. The stage was large enough to house two full-sized sailing ships positioned side-by-side. A specially constructed backdrop mechanism realistically simulated the waves. The stage, numbered 21, was, at the time, the largest sound stage on the Warner Brothers lot and the second largest in Hollywood, second only to MGM's cavernous Stage 15. The Maritime Stage was destroyed by fire in 1951.