The Lost Continent is a 1968 adventure film made by Hammer Films and Seven Arts featuring Eric Porter, Hildegard Knef, Suzanna Leigh, Tony Beckley, and James Cossins. The film was produced, directed and written by Michael Carreras based on Dennis Wheatley's novel Uncharted Seas (1938).
The film sees the crew and passengers of the dilapidated tramp steamer Corita heading from Freetown to Caracas. While the passengers all have their own reasons for getting out of Africa, the captain of the ship is also eager to leave, as he is smuggling a dangerous explosive cargo. Whilst en route to South America the ship is holed and eventually what's left of the crew and passengers find themselves marooned in a mist-enshrouded Sargasso Sea surrounded by killer seaweed, murderous crustaceans and previously marooned descendants of Spanish Conquistadores and pirates.
Plot
Captain Lansen reads the Burial Rites from the Book of Common Prayer watched mournfully by a motley crew of seamen, pirates, Spanish ladies, armoured conquistadors and priests (all seemingly from different time periods). As the shrouded cadaver is slid overboard from beneath a flag the captain asks: "What happened to us? How did we all get here...?"
... On board the tramp steamer Corita, Captain Lansen first ignores a hurricane warning then ignores a customs launch whose crew want to inspect his ship, as he is smuggling the explosive "Phosphor B" ('Phosphore Blanc', i.e. white phosphorus). His ship's passengers, a mix of rich and poor, also have various unwholesome reasons for leaving Freetown: Dr. Webster, together with his daughter Unity, for his indiscretions with patients; an alcoholic conman Harry Tyler with a jacket lined with money; Eva Peters, a trophy wife who has stolen bearer bonds to pay for the ransom on her son in Caracas, and lawyer, Ricaldi, pursuing Eva Peters in order to retrieve those stolen bonds.
An accident nearly sets off the explosives and the authority of the captain comes to a head when an anchor chain slips a gear, ruptures the bulkhead and power is lost. Some of the crew mutiny and take to a lifeboat. Chief Engineer Nick cannot repair the generator and Captain Lansen, fearing the ship may explode with Hurricane Wendy about to engulf them in a storm, takes the remaining crew and passengers into another lifeboat. In the ensuing chaos, Dr. Webster is soon devoured by an attacking shark.
The following morning, Lansen's lifeboat finds itself adrift in a morass of large, sentient and carnivorous seaweed, which kills the cook. The lifeboat later bumps into the Corita again, and its passengers find the propellers of the tramp steamer completely fouled by the pullulating seaweed. Nevertheless, those in the lifeboat are forced to take refuge in the doomed vessel once more. That night, Unity is attacked by a huge glowing-eyed Prehistoric octopus (an over-sized Keuppia), which kills Ricaldi when he attempts to rescue her.
Sarah, a mysterious native girl from a nearby island, suddenly appears, walking on the morass of seaweed, prevented from sinking by air buoyancy balloons attached to her shoulders and odd pads attached to her feet. She is being chased by a bunch of fur-clad barbarians but she warns Captain Lansen of an impending attack. The crew and passengers defend the Corita, with the surviving fur-clad attackers returning to a dilapidated large wooden Spanish galleon, marooned nearby. Child leader "El Supremo", the princely descendant of the Spanish Conquistadors, along with members of the Spanish Inquisition had ordered the attack in order to steal their supplies.