Alan Gaskell (Clark Gable) is an abrasive, gambling, captain of a steamer, the Kin Lung, chugging between Singapore and Hong Kong. Tensions are high before the Kin Lung sails from Hong Kong because pirates are discovered disguised as women passengers while others try to smuggle weapons aboard.

Dolly Portland (Jean Harlow) is Alan's former girlfriend, who Alan later describes at the Captain's table as a "professional entertainer," and travels with her maid (Hattie McDaniel). Meanwhile, another of Alan's former loves, aristocratic Sybil Barclay (Rosalind Russell) from Sussex, England boards the Kin Lung. "I am in your hands again," Sybil taunts Alan, and eventually they plan to marry when the steamer docks in Singapore. However, Dolly tries to win back Alan. Meanwhile, Jamesy McArdle (Wallace Beery) is a corrupt passenger, in league with a gang of pirates planning to steal a gold shipment of gold bullion worth 250,000 GBP carried on the steamer.^[3] Dolly discovers the plot and attempts to warn Capt. Gaskell against McArdle but he deflects her warnings.

In calm seas, following a typhoon in which the ship suffered damage to its cargo and the deaths of some crew, the Kin Lung is boarded by Malay pirates, as McArdle expected and with whom he is in alliance. The pirates steal personal possessions from passengers. Unable to find gold in the ship's strongbox, which Capt. Gaskell has replaced with sand, they torture Capt. Gaskell using a Malay Boot but the captain will not reveal the gold's location. Instead, with bravado, Gaskell instructs the pirates, as they prepare to torture him: "My size is 9C", before fainting from pain. While leaving the ship, minus the gold they intended to steal, the pirate's ship is bombed by Third Officer Davids, who dies while throwing a Mills Bomb as a grenade, which sinks one pirate junk. Their second sinks in the South China Sea after being bombarded by a light cannon manned by Capt. Gaskell.

Frustrated by the failed robbery McArdle commits suicide. When the Kin Lung docks in Singapore, Captain Gaskell, still limping due to his tortured foot, settles that his love for Sybil is superficial. Instead he recognises that Dolly gave him good warning and he loves her more. They decide to marry. He says farewell to Sybil. As the film closes Capt. Gaskell reveals the gold was safe all along, hidden inside the ship's cargo (the toolbox of a steamroller stowed on deck).

• Clark Gable as Captain Alan Gaskell
• Jean Harlow as Dolly 'China Doll' Portland
• Wallace Beery as Jamesy McArdle
• Lewis Stone as Tom Davids
• Rosalind Russell as Sybil Barclay
• Dudley Digges as Dawson
• C. Aubrey Smith as Sir Guy Wilmerding
• Robert Benchley as Charlie McCaleb
• Akim Tamiroff as Paul Romanoff
• William Henry as Rockwell
• Liev De Maigret as Mrs. Vollberg (credited as Live de Maigret)
• Lilian Bond as Mrs. Timmons (credited as Lillian Bond)
• Edward Brophy as Timmons
• Soo Yong as Yu-Lan
• Carol Ann Beery as Carol Ann
• Ivan Lebedeff as Ngah
• Hattie McDaniel as Isabel McCarthy, Dolly's Maid (uncredited)
• Donald Meek as Passenger playing chess (uncredited)
• Willie Fung as Cabin Boy Ah Sing (uncredited)

Irving Thalberg had worked on the film since 1930 when he assigned three different writers to come up with three different treatments. By 1931 Thalberg had decided on the one storyline and spent the next four years working on a script with two dozen writers, half a dozen dir/and three supervisors.^[2]

John Lee Mahin said he and Jim McGuiness were called in by Irving Thalberg to look at the script by Jules Furthman. Mahin said Faurthman "had stolen so much—practically word for word out of famous pieces. Things by Mark Twain and Somerset Maugham—and there was a well-known English novel of the time that he had taken a whole speech from. We discovered these, and we had to do quite a lot of rewriting. Granted, nothing’s new, but Jesus, you don’t just take whole lines of dialogue!"^[4]

Gable had several temper tantrums on the set, which were tolerated by MGM studio chief Louis B. Mayer because the star had recently won an Academy Award for Best Actor in It Happened One Night (1934) on a loan-out to Columbia Pictures, and he did not want to risk losing him. Mayer even tolerated that Gable risked his life by refusing a stunt double in a sequence in which he assisted numerous Chinese extras in roping in a runaway steamroller that crashed up and down the decks of the cantilevered studio ship.^[5]

China Seas was an early Hollywood formula adventure-movie loosely using the plot of Gable and Harlow's earlier film titled Red Dust (1932) featuring Mary Astor in Russell's role, which was subsequently remade with Gable, Ava Gardner and Grace Kelly two decades later as Mogambo (1953).

Wallace Beery had worked with both Gable and Harlow in The Secret Six (1931), in which Gable and Harlow had smaller supporting roles and Beery played the lead. Beery and Gable also appeared together later the same year in the naval aviation film titled Hell Divers (1931), this time with Gable's part almost as large as top-billed star Beery's. The pairing of Gable and Harlow was so popular after Red Dust (1932) that they wound up making six films together, with the final one being finished posthumously after Harlow's untimely death.

The film was a big hit earning $1,710,000 in the US and Canada and $1,157,000 elsewhere resulting in profits of $653,000.^[1][2]

• China Seas at IMDb  
• China Seas at AllMovie
• China Seas at the TCM Movie Database
• China Seas at the American Film Institute Catalog
• China Seas at Rotten Tomatoes  
• China Seas at malayablackandwhite