The ship Bush and Hornblower board to meet the admiral at the end of the movie is the actual HMS Victory, currently dry-docked at Portsmouth, England. As Admiral Horatio Nelson's flagship at Trafalgar, she still commissioned as an official vessel of the Royal Navy, and the only surviving, original ship of the line still in existence.
The rights to the novel were originally acquired by Warners with Errol Flynn in mind, but after the financial failure of Adventures of Don Juan (1948) and growing difficulties with the actor, he was not cast. Warners was already building up Burt Lancaster as its new swashbuckler, but the role of a British sea captain seemed out of his range, so Gregory Peck was ultimately cast.
To save costs, the Hispaniola from Treasure Island (1950) was reused and renamed Lydia but now the ship was rocked instead of the horizon, this caused many problems due to the combined weight of ship's crew and equipment.
Once the flogging of seaman Hommel was complete, salt should have been spread over his back as a (painful but necessary) antiseptic, hence the saying 'rubbing salt in the wound' whenever one trauma follows another.
Hornblower's batman Polwheal is played by Richard Hearne an English actor born to a theatrical family who later in the fifties became better known in Britain for his TV work especially his children's series Mr Pastry.
When Captain Hornblower and his companions reach the town of Nantes they board a British captured vessel called the 'Witch of Endor'. The name comes from a biblical character but only appears in the Jewish version as such, in the Christian version she is known as 'the woman that hath a familiar spirit in En-dor'.
At the beginning of the film the ships blacksmith Quist played by James J (Robertson) Justice bemoans his luck at picking the Navy instead of five years hard labor in prison to some other malcontents working on a deck gun. He then spits on the deck before continuing to speak of a possible mutiny, later when the envoy from Don Julian Alvarado comes on board Quist spits on the deck again. Spitting was an offense punishable by flogging, while incitement to mutiny was an offense punishable by death.