Nearly half of his 67-year lifespan has been spent underwater.
American photographer David Doubilet has spent five decades taking stunning photos of the seas and oceans, photographing more than 70 reports for National Geographic.
He was only eight years old when he went snorkelling at summer camp in the Adirondack Mountains in upstate New York and fell in love with the underwater world.
He said: "All the things that I didn't like about the surface disappeared the moment I put my head underwater. I was looking at a strange new world and it was one that I loved."
At 12, he started taking pictures underwater. At 23, he landed his first National Geographic assignment and found himself in good company, learning from fellow photographers.
"Two of my biggest influences were fellow National Geographic photographers - Luis Marden and Bates Littlehales - who were real mentors to me. Bates developed a new housing, the OceanEye, which pushed the parameters of what we could shoot underwater at the time," he said in a telephone interview.
He has had many memorable moments, including working in the Antarctic Ocean and diving to the sunken wreck of the USS Arizona in Pearl Harbour. But it is those spent with his wife, underwater photojournalist Jennifer Hayes, that he treasures.
He said: "Jennifer is my life. We've worked together on some incredible assignments - there's a river in Africa called the Okavango River which flows into northern Botswana and spills into the Kalahari desert, creating the largest oasis in the world. We worked in the northern part of the river and although visibility only went to about half a metre, the place was incredibly beautiful - like an underwater garden."
Getting that perfect shot that encapsulates the moment is not easy, as Mr Doubilet attests.
"It's that moment when everything comes together. Sometimes, you can anticipate the moment, but it's very rare.
"I remember a dive with Australian sea lions - it was a beautiful thing. They would come into the water and play with you. The water was shallow and clear, there was an endless variety of seaweed, like a green carpet, and everything just came together when the sea lions played. I'll never get that shot again."
Advances in technology have made his work easier. "It's a whole different ball game now with digital cameras," he said.
"I remember doing a story 20 years ago. It was a long 35-day cruise down the length of the Red Sea and we could shoot and stop at any time.
"To do this story, I took 10 underwater cameras - each needed a housing - along with different fronts to each housing and two strobes per housing.
"That meant 10 cameras, 10 housings and 20 strobes. If I had shot every single picture on one dive with 10 cameras, I would have got only 360 pictures.
"Nowadays, no one goes into the water with a card that can shoot 360 pictures. The cameras we carry have been reduced to three, but we now have cards that can shoot a thousand pictures in RAW format. Another thing is that we can immediately see what we shoot, which is a great advantage."
But it is not just technology that makes the photo.
This is what he advised: "The most important thing is for the picture to be intimate. Whether shooting a shrimp or a shark, you have to look deeply into the subject.
"One example I can give of this is the nudibranchs, which look like snails without shells. They are toxic, and advertise this with an ongoing ad campaign - their bodies have the most incredible colour in the world.
"However, they don't swim through the water; they stay on the ground. Most of the pictures taken of them were basically taken looking down at the snails, shooting them from the top down.