Despite the fact that ‘Aquaman’ is expected to swim into theaters on December 21, director James Wan is still putting the final touches on it.  Considering that most of the movie takes place in pseudo-underwater, almost every shot in it is enhanced by CGI of some sort.

When visited Wan in the editing bay recently, he “spewed” a bit about one physiological phenomenon that will be on display in the film– that Atlanteans essentially vomit up water when they come into contact with air.  The scene in question occurs in the film when Mera (Amber Heard) has to create an air bubble underwater.  When Orm (Patrick Wilson) is inside, he begins flopping like a fish and water comes rushing out of his mouth.

“Just from a practical standpoint, people ask me, when they talk, ‘Is it bubbles that come out of their mouth?’  No, ’cause there’s no air in your lungs, so there wouldn’t be any bubbles, right? Because you don’t do that, right? And, so, then, in that sequence, where you saw Mera open up this air pocket to suck Orm away from Arthur, help him out, now, when he’s breathing, the first thing he does is he using the air pockets, where he could get out all of the water that’s in his lungs.”

This doesn’t explain why Queen Atlanna (Nicole Kidman) is shown in flashbacks breathing just dandy on land.  Hopefully, the film will provide an adequate reason for that and not leave a plot hole.

Considering that ‘Aquaman’ was filmed on dry land, CGI will be used to make everything appear as though it’s underwater.  But how do you believably make the performers appear as though they are truly submerged?  Wan revealed:

“It is very difficult just trying to simulate that, the look of weightlessness that you would get under water, but we did tons of R&D very early on.  With how people would move under water… We’re still very much limited by what we’re capable of doing, because we’re normal human beings. We’re not Atlantean, right? These guys, obviously, move very differently in a water space, in that space. To them, they’re basically like super heroes, but, for us, we swim slowly.”

Directed by James Wan, ‘Aquaman’ stars Jason Momoa, Amber Heard, Patrick Wilson, Yahya Abdul-Mateen II, Michael Beach, Willem Dafoe, Djimon Hounsou, Dolph Lundgren, Graham McTavish, Temuera Morrison, Randall Park, and Nicole Kidman, and swims into theaters on December 21, 2018.