I watched Aquaman about two weeks ago. I taped it when it was on HBO. It has Jason Momoa, Amber Heard, Patrick Wilson, Temuera Morrison, and Nicole Kidman in it.
Big Warning: there is some violence.
In this movie, a man named Tom saves a woman laying on the beach. She is actually a queen of the sea. They fall in love and have a son. But her husband comes to find her and she leaves to protect her son and Tom. The son becomes a hybrid and he can protest to have a seat of the sea throne. His half brother wants the throne and wants to kill the humans. Arthur fights his half brother and goes on a journey to find the lost trident. He ends up finding his mother who is still alive. He does win the throne.
I loved this movie.