Skyfall, the next James Bond movie, is going to have some serious underwater fights. They have been filmed in the only underwater stage in the planet, a 20-by-10-meter pool that is almost 20 feet deep and contains 317,006 gallons (1.2 million liters) of water.
The whole mechanics on how they prepare and film theses scenes—using high quality underwater sparkers, underwater monitors and dive buddies, so nobody has to go up to the surface for hours—is quite fascinating.
And it's always cool to see Daniel Craig doing the stunts. [Mashable]