It looks like Warner Bros. doesn't want to climb out of the water just yet. New reports indicate that a spin-off to 2018's Aquaman, called The Trench, is in the works..
The Jason Momoa-starring flick was a major success for the studio, so the interest in more Atlantis-adjacent content is not unexpected. The movie totally dominated the box office, generating over $1 billion worldwide. (As far as superhero movies go, that's a feat typically reserved for Marvel, with Avengers: Infinity War, The Avengers, Avengers: Age of Ultron, Black Panther, Iron Man 3, and Captain America: Civil War all having hit the mark. Aquaman was the first film in the DC universe to have reached the milestone since 2012's The Dark Knight Rises.)
According to The Hollywood Reporter, the studio has enlisted two writers, Noah Gardner and Aidan Fitzgerald, to work on a script for The Trench. Aquaman producer Peter Safran and director James Wan are both on board to produce.