Image Gallery: The Perfect Underwater Photo

For nearly 35 years, National Geographic photojournalist Brian Skerry has been immersing himself in the big blue to get the perfect underwater photograph. He admits that there will never will be a "perfect" photo, but there are tricks to make a photo appealing. He sees himself as an artistic interpreter, swimming in waters all over the world to shoot ocean images that capture animal behavior, stunning seascapes, and the graceful gestures and fluidity of his subjects.

In his second blog post for the Smithsonian Ocean Portal, "The Perfect Underwater Photo," Skerry shares some of his secrets of the trade.