This was the first Rank Organisation film in CinemaScope. It was filmed entirely on location in Hong Kong and Macao and at sea between the two ports, and it cost £500,000, making it the most expensive Rank film ever, to that time. It was a box-office and critical flop.
Originally Curd Jürgens was to play Captain Hart and Peter Finch Mark Conrad. Rank replaced Jürgens with Orson Welles and had him play Conrad instead, firing Finch. Finch had had a recent spate of box office duds, but in The Man Who Ruined the British Film Industry (1996), Lewis Gilbert suggests it was because he had clashed with Rank impresario John Davis.
Orson Welles and Curd Jürgens quarreled badly during filming. This was as a result of Welles' playing his character as a buffoon (rewriting a number of his own lines), and treating the story as a comedy, whereas Jurgens saw it as high drama, as had the producers.
So bad was the relationship between Curd Jürgens and Orson Welles, that director Lewis Gilbert was forced to film their scenes separately.
As is already noted (and confirmed in Orson Welles's book 'This is Orson Welles' compiled by Peter Bogdanovich), Welles played his role for comedy while the film carries an adventure/drama combo. Then again, it is a lightweight film and in many ways resembles a romantic comedy, especially given the subplot with Sylvia Syms and Curd Jürgens throughout. Welles's performance, then, seems more catered to slapstick-comedy than normal comedy. Either way, he's deliberately out of sync with the rest of the picture. Many critics as well as Welles fans have considered it his worst performance.