[He stops, shovel blade down, and crosses his arms atop the handle, leaning against it and just watching her for a moment.]

Sister, you looked outside at all? There's millions of gallons of water out there. If we could escape, we'd all be crushed before we ever made it up there, and if we did make it up, we'd all die of the bends. Who the hell cares what we're doin' down here? Until we figure out where the subs are, nobody's leavin' except how we came, and on that one, your guess is just as good as mine.