World's Largest Cottonmouth?

The Mossy Oak film crew recently posted this video, titled "World's Largest Cottonmouth Snake," on YouTube. Here's the info they published with the clip:

"What would you do in this situation? The Mossy Oak crew came across this venomous cottonmouth (water moccasin) while out planting a duck hole in the summer. You just never know what you might run into down here in the south. "

It's definitely a big snake, but it's hard to tell just how big in this clip. And, there are some snake stories on the web that that claim some pretty massive serpents.

What do you think? Is this the biggest cottonmouth you've ever seen?