"The film begins moments after the sinking of the Titanic."

"All who have drowned are brought back to life by a futuristic race of mermaids, called the Mantocks, who welcome the humans to their underwater paradise. Soon after, JACK DAWSON is elected king of the underwater humans. DAWSON requests that all humans be returned above water, a request that is denied by KING MANTROCK. The humans are slowly brainwashed into worshiping their mermaid saviors. Meanwhile, the sunken TITANIC has become a haunted underwater wasteland inhabited by RAGGARO and his band of mermaid pirates. Will the humans ever free themselves from their mermaid slavery? Will the mermaid pirates wage war on Mantock?"

(Via Cinematical, via NY Mag.)