Battleship doesn't just show the U.S. Navy locked in combat with alien monsters — it's also changed the way the Navy would respond to an alien invasion in real life.

In our interview with Peter Berg and actress Brooklyn Decker the director reveals a few of the battles he won while arguing with his Naval advisors on set. Also guess what lessons Berg learned from Kevin Costner's Waterworld. And were those alien cannon pegs made to look like the board game on purpose? Find out now in our exclusive WonderCon interview.

Did you meet with anyone from the Navy to see how they would handle an invasion of this type?

Peter Berg: Certainly, I have a great relationship with the Department of Defense starting with Admiral Dennis Moynihan, he's a big fancy Admiral at the Pentagon. And he put about five or six of his Destroyer Captains in touch with us, and they spent a lot of time on the ship. They made sure we got everything right, and we couldn't do anything wrong. But because we were fighting aliens they don't have a playbook for that. So I was able to kind of win a few arguments with some of the Navy Captains that we worked with because [I would say] "Well, how do you know what you do? You don't it's impossible, it's never happened!"

Could you share one argument you won?

Peter Berg: I argued that... the missiles that these ships fire have to be generally fired at a distance of over 20 miles. But I argued that in the event of an alien ship coming at you, you might break that rule and even fire at point blank. So we get to fire some missiles at very close range. It's a bit more dangerous than the Navy would like to see, but because of the extreme extenuating circumstances, they let us.

Did you design the alien cannons to look like the red pegs from the board game?

Peter Berg: I'm not telling you that! Why would I answer that question?

What advice did you get about filming on water?

Peter Berg:I got it from Kevin Costner, he called me about a month before we started shooting. I'd never met Kevin, and he was a great guy. He did Waterworld and he has a lot of problems with sets getting wiped out and stuff. He talked to me for two hours and he told me everything he did right and everything he did wrong, it was a great phone call.

What was the best piece of advice he gave you?

Peter Berg: Have three of everything. Because two will break. And be ready to go with three.