‘My wife wanted to take a picture of me with a yellowtail. She said “Smile!” and pressed the button. When she looked up, I was gone’

It was an early start on Easter Sunday. My wife, Trish, and I were going out on our boat, a 30-footer called The Dive Inn, for a day’s fishing. We’d decided to head to some islands off the coast of Mexico, about 20 miles from our home in San Diego. We left around 5am. Almost every weekend we go diving or fishing – I’ve been fishing for over 30 years – and we normally catch tuna, yellowtail or white sea bass. That day we caught five yellowtail. By early afternoon, the water had turned choppy, so we headed back to port.

We usually clean our fish outside the harbour, but that day we decided to go into the bay, where it was calmer. We saw a few sea lions. We’re always careful not to attract them by throwing fish guts overboard. Before Trish began the final fish, she said she wanted to take my picture. I grabbed a fish and hoisted it up. The sun was reflecting off her cellphone screen, so she was really concentrating. She said “Smile!” and pressed the button. When she looked up, I was gone.

What Trish hadn’t seen was that at the moment she said “Smile!” a sea lion had leapt about 7ft out of the water to get the fish, and grabbed my left hand in the process. Sea lions have canine teeth, just like a dog. It dragged me headfirst into the water. I’d actually seen it out of the corner of my eye a split second before I felt the pain. It was big and had such strength. It pulled me straight down to the bottom of the bay, about 25-30ft. I was moving incredibly fast through the water. It whipped me back and forth five or six times. I thought, “Well, now you know how you are going to die.”

Facebook Twitter Pinterest Dan Carlin: ‘What Trish hadn’t seen was that at the moment she said, ‘Smile!’ a sea lion had leapt about 7ft out of the water to get the fish.” Photograph: Trish Carlin

I was in survival mode. I was fighting to get my hand free, and after a lot of struggling, it finally let me go. I was kicking to get back to the surface when it swam back and took a bite out of my ankle.

My experience of free-diving saved my life. When I went over, I didn’t open my mouth. If you do, seawater forces its way into your lungs and you sink like a rock. The water pressure could have blown out my eardrums, but I equalised the pressure by swallowing. When I surfaced I could hear my wife screaming my name. The whole thing lasted no more than 25 seconds. I climbed the ladder on to the boat and lay down. Every breath felt like agony. There was a huge hole in my hand, the blood was gushing out. Trish wrapped it in a towel. I knew I had to get to hospital, but first we had to hoist the anchor up the last 6ft.

When we pulled in, Trish called 911 and said, “My husband has been attacked by a sea lion.” On the way to hospital, she remembered she’d been taking a picture when it happened – she looked on her cellphone and there it was: me, holding the fish, and a sea lion mid-air, its mouth around my hand. We laughed, but it could have been the final image of me. At the hospital, people kept coming in – not to look after me, but to see the photo.

I was in hospital for two days. I had a cut on my hand from my knuckle to wrist, exposing the bone. I had another, golf ball-sized hole on the other side, and a broken bone in my hand. I needed 20 stitches. A big threat was infection from a nasty bacteria that lives in the mouths of sea lions. The doctor said he’d never seen an injury that severe without massive tendon and ligament damage.

Sea lions are so agile. I don’t buy the idea that it accidentally got my hand; I think it was angry and territorial. The supply of fish here is dwindling and their numbers are increasing – there’s not enough food for them all.

The first night at home, Trish said I ended up screaming in my sleep. But I can see the funny side. The picture is my screensaver and my colleagues have joked about getting me a stuffed sea lion. But they’re not as cute as they look, you know.

• As told to Sophie Haydock

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