Incredible footage shows man rescued after 438 days at sea surviving only on raw fish and birds

Warning: Contains brief reference to suicide and animal cruelty some readers may find upsetting

Eye-opening footage shows a real-life castaway returning to civilization after spending more than a year lost at sea.

Salvador Alvarenga and his acquaintance Ezequiel Córdoba had only expected to be gone for a day or two when they set off from Mexico on a fishing trip on November 17, 2012.

Alvarenga, then 35, was an experienced fisherman and knew a storm was coming, but he'd been through enough before that it didn't concern him.

“It wasn’t the storm that was the problem,” Alvarenga said more than a year after he set off, per CNN. “My engine gave out.”

The pair found themselves adrift as the storm bashed at their boat for seven days, during which Alvarenga lost his radio and fishing gear. By the time the storm was over, the boat was far from Mexico.

With nothing but an ice box used to store the fish on board, the two men were initially forced to drink their own urine to try and satiate their thirst.

Later, when seabirds began to start resting on their boat, the men would cut their throats and drink their blood.

The boat had no roof or shelter. (STR/AFP via Getty Images)

The only food available was the birds and fish in the water surrounding the boat.

Thankfully, Alvarenga's fishing skills meant he was adept at catching fish even with no hooks or lines, but they would still go for days at a time without anything to eat.

Tragically Córdoba, who was only 22 at the time the boat went missing, died as the two men drifted at sea.

“We said our goodbyes. He wasn’t in pain. He was calm. He didn’t suffer," Alvarenga said later.

Now alone on the boat, Alvarenga did his best to signal to any passing vessels, but never managed to get their attention. At times, he said he considered taking his own life.

It wasn't until after 438 days of endless ocean that Alvangera saw mountains rising up from one of the Marshall Islands. When he got close enough, he dove into the water and began to make his way to try land.

Alvarenga was flocked by reporters after returning. (ELIZABETH RUIZ/AFP via Getty Images)

"I hit the ground first. My boat hit the ground second," he said. "I felt the waves, I felt the sand, and I felt the shore. I was so happy that I fainted on the sand. I didn’t care if I died at that point. I was so relieved. I knew at that point I didn’t have to eat any more fish if I didn’t want to."

After being found by residents near the beach, Alvarenga was transported by boat the Marshall Islands’ biggest hospital.

As he stepped off the vessel, he was greeted by cameras and reporters desperate to hear his incredible story.

There were some people who didn't believe he could possibly have survived for so long, but Alvarenga didn't care.

After being rescued, he said he's simply 'happy to be alive'.

He was 'afraid' of the ocean afterwards, describing it as 'haunting'. But after spending months by himself, he was just 'happy to be with [his] family'.

If you or someone you know is struggling or in a mental health crisis, help is available through Mental Health America. Call or text 988 or chat 988lifeline.org. You can also reach Crisis Text Line by texting MHA to 741741.