A current and famous example for a messianic Poseidon-figure is the hero of Aquaman in the Marvel-movie Justice League (USA, Snyder 2017), in which Poseidon is shown as a superhero.
In the plot, he is a king who rules over the sunken empire of Atlantis, and he also has a five times jagged trident, with which he is able to cause big waves to fight against tyrannical enemies like the Parademons. Furthermore, he is a very fast swimmer and can talk to fish and other animals that live in the sea.
As far as his iconography is concerned, he looks like the Poseidon statues of fountains of the Renaissance: He has a beard, long and curly hair, and an athletic body. By having bright sea-blue eyes, blond-brown hair, tanned skin, and fish-scale-tattoos all over his strong body, he is also modernized and hybridised with a handsome surfer boy.
If you wish to get to know the power of Aquaman-Poseidon, you can watch this stranger, raising from the sea:
Found by Dr. Michael Stierstorfer from the University of Regensburg.