When Hornblower, with his men, are locked in the stocks, he urges them to break free by saying "Two, six, heave". This is a British Royal Navy phrase used to coordinate seamen's pulling.
In this adaptation of the book, the French major is needed as translator. In both the book and earlier TV series, Hornblower speaks fluent French.
When the men are signing in, it is possible to tell that, according to the log, Styles is 32 years old, has 18 of experience and he's illiterate (he signs using an "X"), while Matthews is 45 with 33 years of experience and can read and write.
The brown print day dress worn by Julia Sawalha (Maria) is the same costume worn by Cécile Paoli (Lucille) in Sharpe's Waterloo (1997).
The white and blue print gown Julia Sawalha (Maria) wears to church is the same costume worn by a guest at the Easter Ball in Wives and Daughters (1999).