A sea lion jumped from the water as a man posed for a photo on his boat with a large fish and pulled him overboard.
Dan Carlin is still recovering more than three weeks after the incident in Mission Bay, San Diego.
He told how his wife Trish had just told him to smile for the camera as he held a yellowtail fish on their 29ft boat.
The sea lion leapt seven feet from the water, locked onto his hand holding the fish and yanked him into the ocean.
He smashed into the boat’s side and was taken some 20ft underwater, and the 62-year-old San Diego accountant said the sea lion whipped him from side to side.
Mr Carlin said: “After 15 seconds, I thought I was going to die.
“I continued to struggle, but thought this is the way I was going to die. It was unbelievable to me.”
Then, as quickly as the attack happened, Mr Carlin was released. He swam toward the surface as the sea lion bit his foot, puncturing a bone.
He managed to make his way back to his boat. He and his wife moved it closer to land while his hand gushed blood and he struggled to breathe because of his battered chest. At one point, he said, he lost his vision.
He spent two days in hospital and the gash on his hand required 20 stitches after the April 5 incident.
Mr Carlin hopes his hand will have healed enough so he can go back out fishing next week.
An experienced surfer, scuba diver and fisherman, he said he and his wife always took precautions to properly dispose of any guts or carcasses to ensure they did not go in the water.
But he said his experience shows just how dangerous sea lions can be, despite the fact that people often do not fear them.