Aquaman (2018)

Directed by James Wan, Aquaman (2018) stars Jason Momoa as Arthur Curry, heir to the underwater kingdom of Atlantis. As tensions rise between the surface world and the oceans, Arthur must confront his royal lineage and challenge his half-brother for the throne. Based on the DC Comics character, the film combines large-scale action, fantasy world-building, and superhero mythology within the DC Extended Universe.

Från IMDB:
Arthur Curry, the human-born heir to the underwater kingdom of Atlantis, goes on a quest to prevent a war between the worlds of ocean and land.