Movie: What happened to Indiana Jones when the submarine went down?

I guess hardly anyone has managed not to hear that there's a new Indiana Jones movie out. Perhaps you've even seen it. I haven't. But I remember seeing the first one in 1981 and ever since I have wondered: What happened to Indiana Jones when the submarine went down? I now know that I wasn't alone. Look below and find out what happened. (this post has been edited and updated in 2015 and in 2024)

---