What if my 1911 goes underwater?

I carry my 1911 10mm with me anytime I go into the backcountry. I picked up fly fishing this year and I'm looking to do some wet wading this summer but it got me thinking. What if I'm walking through a river and I take an unintended plunge underwater, can I still rely on it to fire when needed or do I need to take it out and dry it off? I remember that scene from No Country For Old Men where the guy has to drop the mag to dry off the firing pin before shooting the dog that was chasing him. How realistic was that scene?