Santiago Cabrera (Transformers: The Last Knight, The Muskateers) was cast as Aquaman/Arthur Curry. In the film, Aquaman had come to the aid of mankind before and lost his hand for his troubles. Now the King of Atlantis has a prosthetic water hand, similar to the one he had in the comics.
Aquaman isn’t wearing his body armour that was seen in previously released concept art. He has a boney structure down the front of his torso, a bit like a fish. From the leaked script, Aquaman is stung by a robot mosquito which gives him aquaphobia. He tears off his water hand and throws it aside. However, the Manhunter is able to use the water hand as a suit of water armour which will prevent him from bursting into flames.