Off the coast of Cape Town, South Africa, two powerful ocean currents meet. The cold Benguela Current in the west mixes with the warm Agulhas Current at the tip of the continent, resulting in an area rich with marine biodiversity.

The rugged coastline also produces powerful swells at a place where the reefs come out of deep water, making it the perfect playground for fur seals—social, playful creatures that surf the waves like dolphins, just for fun.

Photographer Thomas Peschak had been watching these seals for years and wanted to take a photograph of them surfing from a unique underwater perspective—but first he had to figure out how to do it without getting himself seriously injured or killed.

“When waves were really big and the seals were surfing almost constantly it was near suicidal to get into the water. You would get smashed by the surf and drilled into the rock,” he said. “I saw a lot of days with dramatic photo potential, but the waves were just too big. Then on the days when it was safe the seals weren’t surfing or the water was murky.”

View Images Thomas Peschak photographs surfing seals off the coast of Cape Town, South Africa. The water is cold (53 degrees F) and he wears a thick wetsuit and carries a weight belt while freediving to make his images. Photograph by Steve Benjamin

Then one day he and his assistant Steve Benjamin went to the coast for another shoot, not intending to photograph seals at all. But the sea that day was perfect. There was no wind, the ocean was glassy smooth and perfectly sized sets of large waves rolled in. And most importantly, the seals were surfing en masse.

Most of Peschak’s assignments include underwater photography, but he only rarely uses SCUBA gear. Instead he prefers to free dive—just holding his breath and coming up for air every few minutes. He headed towards the ledge where the waves were breaking and repeatedly dove under waiting for a squadron of seals to surf directly over his head. His assistant stayed out of the impact zone, constantly scanning the horizon. When Benjamin saw a clean-up set coming (an extra large set of waves) he would scream at Peschak: “Get out of there, NOW!”

Watch fur seals surfing underwater off the coast of South Africa.

Video by Steve Benjamin.

“Whenever I returned to the surface to catch my breath and heard screaming I dove again almost immediately and swam as fast as I could to deep water, waiting for the barrage of waves to pass. Often it felt like playing chicken with a freight train,” Peschak said.

Peschak kept at it for more than three hours, getting tossed and tumbled by the waves. He would hit the motor drive on his heavy camera, surface, swim into the channel, wrap his leg around a kelp plant to look at his images, then go back down again and again.

“The seals are a fast. They are a blur. So I shot thousands and thousands of images,” he said. “You might get off three frames before the seal has already surfed past you.”

After hours of fighting the waves, Peschak was exhausted, but he just kept shooting.

“I don’t know when to stop sometimes,” he said. “You are only seeing the frames on a small LCD, and that’s not always the best to judge by. I kept shooting for another hour or so, because I wasn’t sure I had it.”

View Images Fur seals surf in the Table Mountain National Park Marine Protected Area, off the coast of Cape Town, South Africa. “They are a really great indicator of the bounty of life that can be found in the realm of the Benguela current,” says Peschak. “It is cold, rich water that sustains life.” Photograph by Thomas P. Peschak

But indeed he did. The resulting photos showcase the raw power of the waves, and the playfulness and energy of the seals.

“When you try to take an image that no one has taken before there is a lot of trial and error,” he said. “If it was easy, this photograph would have been taken years ago. It’s about persevering and trying to be creative until your stubbornness is rewarded by Mother Nature.”

This month’s National Geographic magazine story “Cross Currents” features Peschak’s images from Southern Africa’s Marine Reserves. You can also see more of his work on his website.