Our Flag Means Death season 2 shot a crucial scene in the Avatar 2 tank

polygon.com:

Season 2 of David Jenkins’ pirate comedy-romance-drama Our Flag Means Death has finally premiered on Max, with an opening three-episode arc that’s guaranteed to get the series’ fandom buzzing. The third episode in particular ends with a sequence that feels like it was intentionally crafted to inspire the crowds of fan artists who have turned the series into an obsession. Polygon talked to the series’ VFX supervisor, David Van Dyke, about what went into shooting that sequence — and how James Cameron’s Avatar: The Way of Water helped out.

[Ed. note: Spoilers ahead for season 2, episode 3 of Our Flag Means Death.]

At the end of episode 3, Ed “Blackbeard” Teach (Taika Waititi) is in limbo after being assaulted and nearly killed by his crew. There, he meets his former captain Benjamin Hornigold (another of the series’ historical pirate characters, played by Mark Mitchinson), who tries to help him through his emotional crisis over being abandoned by Stede Bonnet (Rhys Darby). Except Hornigold mostly helps by pointing out Blackbeard’s failings, then tying a stone to his waist and throwing him off a cliff into the sea — where he sees a vision of Stede as a fish-tailed merman, coming to save him.

“Just so you know, Rhys and Taika did very well underwater,” Van Dyke told Polygon about shooting the scene. “Rhys is not an Olympic synchronized swimmer, but he’s a strong swimmer. They were both very comfortable underwater. They both did a really good job of being mermen.”

Van Dyke says he was originally asked whether he could do the scene with CG versions of the two men, for safety reasons. He explained that it was possible, “but that’ll cost millions and millions of dollars, and we don’t really have that.”

Instead, he ended up