
Captain Lansen (Eric Porter), along with his crew and a motley assortment of passengers are traveling aboard the Corita, bound for Caracas. The captain is set on sailing straight to the destination and avoiding any stops and/or possible inspections. Unknown to the passengers and most of the crew, the ship is transporting dangerous material that will explode if it has contact with water. When a freak accident causes the anchor to punch holes in the side of the ship (and in the very same room storing barrels of the aforementioned material), there is a mutiny from most of the crew, and everyone must abandon ship. Things only get worse, as the survivors drift to an apparently deserted land of strange creatures, killer seaweed, and Spanish soldiers who answer to El Supremo (Darryl Read), a leader who appears to be no more than a child -- and “hardly old enough to wipe his own bottom,” as according to the Chief (James Cossins).
One great aspect of The Lost Continent is that it seems to embrace the idea of “out of the frying pan and into the fire.” Once the people aboard the Corita learn that it might explode, they are quickly burdened by the crew’s mutiny. Safely on the lifeboat, the people then must cope with flesh-eating seawood, and eluding that merely takes them to a foreign land of new, unheard of dangers. The plot moves at a frantic pace, and it tends to feel as if the characters are running away from something. In fact, the film establishes that the passengers are traveling on the ship to escape: a doctor with legal troubles, an alcoholic, etc. When they are informed of a forthcoming storm, none of the passengers want the captain to turn the ship around.

The Lost Continent is full of Hammer alumni. Director Carreras, who also produced and wrote the screenplay (under the pseudonym Michael Nash), had worked on a number of Hammer films in the capacity of producer and director. He was also the son of Hammer co-founder James Carreras. Porter was the star of the terrific and vastly underrated Hammer production, Hands of the Ripper (1971), and the same year, Suzanna Leigh, playing one of the passengers in The Lost Continent, appeared in Lust for a Vampire. Even author Dennis Wheatley, whose novel, Uncharted Seas, provided the basis for the adaptation, had other books made into films by Hammer studios, such as The Devil Rides Out (1968) and To the Devil a Daughter (1976). (Another of the passengers, played by Nigel Stock, is reading Uncharted Seas while on the ship.)
