Nate should have died at least once (spoiler)
He gets hit in the head with a butt of a rifle and falls in the sea. Yeah, he's dead. He does not swim up few minutes later. No, he's pretty much dead.
shareIf he was knocked unconscious by that blow he would surely have died in the water.
This tells us he was not knocked unconscious.
Also, time has been known to pass off-screen. It's entirely possible he was not in suspended animation underwater, waiting for the camera to be on him so he could surface.
My guess is he swam away from the guy with the gun and made his way to the dock and safety.
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