According to Polaroid, founder Edwin Land conceptualized their beloved instant camera in 1943, when his three-year-old daughter asked him why she couldn’t see a photograph he had just taken of her. A few years later, when Land had created and marketed instant cameras to the public, they were quickly embraced for their ease. No messy darkroom, no waiting to see if you got the shot.

What they weren’t known for was underwater photography.

But in 2007 (ironically just a year before Polaroid stopped manufacturing instant film) Mauritian twins Ian and Erick Regnard began taking Polaroid possibilities to a deeper level.

View Images Blacktip reef sharks in Tahiti

The Regnards, who started out as surf photographers before branching into portraiture and lifestyle work, wanted to use large-format film to shoot nudes swimming with stingrays. (You can check those out on their site.) They were comfortable working with PN55 Polaroid film, so they tried doing something that hadn’t been done before—waterproofing a large-format Polaroid camera.

View Images Stingrays

“The research and development was difficult,” says Ian. The process was a balancing act. The film had to be changed after each shot, so the casing needed to allow easy access. The Polaroid film sleeve needed space inside the housing, which meant adding over 30 pounds of weight to prevent the case from floating. And so on.

View Images Blacktip reef sharks

Then there was the issue of focusing the encased camera. “It’s very complicated when you need to shoot moving objects,” Ian says. So they created a formula by photographing a giant ruler underwater and recording the correlation between the camera setting and where the focus fell on the ruler. The calculations enabled them to focus their lens based on the distance of their subject from the camera.

View Images Stingray

While the Regnards were aiming their innovative camera setup on their original subject—models and stingrays in the clear, shallow waters of Tahiti—they had visitors. “Sharks, curious as they are, started to circle around us,” Ian says. But not in a Jaws kind of way. “The blacktip reef sharks were fairly small.” So they expanded their repertoire. “We’re not so much interested in wildlife but in great photos. The sharks were great subjects.”

View Images Blacktip reef sharks

These beautiful photos don’t come completely without risk. One of their subjects, Joe the Barracuda, mauled a man (he was waving food around) two months before the Regnards photographed it. “The barracuda is an aggressive, unpredictable fish,” Ian says. “He was suffering a spear gun injury from a diver, so he was a bit on edge.” This made them very uneasy to get in the water and photograph him. “As you can see from the shot, he came very close to the camera.”

View Images Barracuda

The brothers are clearly dedicated to their art and the methods behind it. The process is painstakingly slow. They make one picture per hour, usually working eight-hour days. It’s kind of the antithesis of modern digital photography practice, but they say it’s worth it.

“The film itself is a beautiful medium,” Ian says. “It produces great photos and has quite a unique border. No two photos are the same.”

With PN55 no longer on the market, these days the brothers’ film of choice isn’t really an option. However, says Ian, “a couple of companies are now making similar film, which we’ll be testing soon.” It seems the Regnards aren’t the only ones who see new potential in the time-honored tradition of instant film.

Ian and Erick Regnard are based in Australia. See more of their work on their website.