When Eric Martin spotted two great white sharks Friday from the Manhattan Beach Pier, he set out to do what he has always wanted to do: swim with the apex predators.



First he put on a wetsuit, grabbed his mask and a long pole he said would be "my defense" if either of the sharks became too aggressive.



Then Martin waded into the surf and swam to an area alongside the middle of the South Bay pier, where people were gazing down at the sharks.



Visibility was poor but the larger shark, measuring about 9 feet, made a pass directly beneath Martin. He could only make out its tail.



Then the same shark made a closer pass alongside Martin.



He said he could see in vivid detail its gill slits, the different shading of its skin and, of course, a slightly open mouth bristling with razor-sharp teeth.

Then, with a few kicks of its tail, the shark disappeared into deeper water.



Unfortunately, Martin did not have his GoPro camera handy. But the accompanying image, shot with a camera phone by a pier visitor named Dani Baker, shows how close Martin was to the shark.



"You can't really tell the size from the pier because you're 30-35 feet up," Martin said. "Let me tell you, they are girthy when you see them up-close."



Why would Martin, a married father of one, take such a risk?



To prove a point, sort of. Martin is not some nut off the street.



He's co-director of the Roundhouse Marine Studies Lab and Aquarium at the end of the pier. He has seen dozens of white sharks from the pier, many times swimming near unsuspecting surfers.



Southern California waters are home to juvenile white sharks–those measuring to about 12 feet–for much of the year. They feed on fish, and if they posed a serious threat to surfers and swimmers, attacks would occur frequently.



Even adult white sharks, which feed largely by ambushing seals and sea lions with upward strikes, will not generally attack a diver simply because a diver is in the water with them.



Divers have been free-swimming with great whites for the past few years, so far without incident, at Guadalupe Island off Baja California, and at other white shark-diving locations.



So Martin proved his point. But mostly, he said, he satisfied his curiosity.



"I've always wanted to do that and it was so awesome," he said. "But I wish I would have had the GoPro."

–Photo courtesy of Dani Baker