He's gained back the extreme weight he lost, re-married and gotten back on the water after the harrowing and incredible test of survival. But his life has very much been split into before and after.

'Since this happened in 1982, it's never left me,' he told Mail Sport in an exclusive interview. 

'Now, I'm 72 years old, this is something that's two and a half months of my life from when I was 30. 'And although I have, I don't know, an affinity for the story and what it means, which is more than about me, it's really about senses of connection to everything, and just being a small part in the larger, incredible universe we live in.'

That story is told in documentary '76 Days Adrift,' which was shown at New York's DOC NYC festival late last year and showcases the mental fortitude and resourcefulness that Callahan needed to survive - as well his ever-growing connection with the ecosystem that formed around him on the sea.

Callahan was 29 years old and recovering from a 'lost' marriage when he set sail on his boat, Napoleon Solo, from Newport, Rhode Island to England with a friend, with Antigua set as the eventual return destination for him alone.

But disaster struck his self-constructed boat in the Canary Islands, leaving him with a dangerously low food supply, a six-person life raft, several other gadgets (such as flares and solar stills to distill seawater) and above all - the looming threat of death.

Callahan ultimately plugged enough holes (sometimes literally), taught himself how to use the solar stills and caught enough food to just barely survive until he was rescued by fishermen on the island of Marie Galant, southeast of Guadalupe. In fact, it was the ecosystem of marine life that had formed around his raft which drew a swarm of birds above - and attracted the attention of his eventual saviors, who correctly figured that fish were nearby.

'Yes, it was a horrible event, but I saw things, I witnessed things, I learned things about the world and about myself that I could only have done in by going through that,' he said. 'I guess if there's a hopeful message to people, it is that: we go through all these things, but hidden within them are opportunities and gifts, and that includes talking to you right this minute, and doing the film.'