that sounds reasonable and would still be plenty of gas for them to share in an emergency considering they need to have a 0.5 bar reserve on surfacingBased on the previous movie, that 2 bar of air showing in the new trailer should last through the whole movie.

That cardboard ad looks nice!
I hope the shark does not stuck to the bottom if that's on scale, there may not be enough water for him to get by

"Mega Shark vs. Giant Plot Hole" would be catchy title for this for the international release
