Alec Guinness made this movie during the two month break in the shooting of Lawrence of Arabia (1962), when the production moved from Jordan to Spain. Upon finishing "Damn the Defiant!" Guinness resumed his role of Prince Faisal.
The tune to which the sailors dance the hornpipe is Cock O' the North, by an unknown composer. There is no printed record of it prior to 1816, but it is quite possible that it was known as a folk tune during or prior to 1797.
The H.M.S. Defiant was mistaken as a real wartime vessel by the Production Crew of Star Trek: Enterprise, who framed and posted a painting of the ship as set dressing in the fourth season episode :Through a Mirror, Darkly".