Main character ... bad
I don't know if my problem is with Bale or with Dieter, but the character as written, and as acted by Bale, was just a loser. He doesn't project indominatable high spirits; rather, he projects smart-ass overconfidence and a twinge of hyperactive narcissism bordering on insanity.
Surviving his ordeal doesn't make him a hero, which makes the over-the-top ending back on his home aircraft carrier a celebration for a dildo. The character doesn't "serious up" long enough for us to feel ANY of his distress, self-doubt, fear and agony. Either he had none of these human frailties - in which case he was only a grinning sociopath; or the script didn't capture the real Dieter's purported humanity. This guy is a joke, and a joker, all the way through the film. The only human feeling he projected was in rare "survival tenderness" scenes with Zahn, and in his short prayer asking God to help them in their desperation. But that's all, in a long, long, movie. If only this film had featured a truly sympathetic, deep, complex protagonist. If only.