A South African big wave surfer has created history by being the first to paddle solo across the Atlantic Ocean on a modified stand-up paddle board.

Chris Bertish began his voyage 93 days ago from Agadir, Morocco, covering 4,050 miles to finish early Friday in Antigua, in the Caribbean.

The 42-year-old former professional big wave competitor - he won the 2010 Mavericks competition and was among the first to paddle Jaws - described the voyage as "the most frightening thing that I've ever done before" during an impromptu press conference on the beach shortly after finishing.

Bertish battled large waves and larger sharks during the crossing (Facebook: Chris Bertish)

"It seems mind-boggling that I'm alive at all to be honest," Bertish said.

"I pretty much ate exactly the same thing every single day for 93 days. It made me realise how much we have and how much we take for granted."

Bertish battled open ocean currents, waves and sharks during the voyage, which he undertook on a custom-made paddle board which featured a watertight cabin, solar panels and GPS.

He kept an online blog throughout the voyage and detailed one close encounter with a great white he narrowly avoided after jumping off the board for a quick swim.

"I had a weird premonition and glanced up just as something caught my eye," Bertish posted.

Something dark [was] disturbing the water moving at speed directly towards the stern of the ImpiFish (the name of his board).

As it got to the point of impact, it veered aggressively to the left and I knew then instantly exactly what it was.

I could see her clearly, a big, dark yet sleek hunting machine.

The living conditions inside Bertish's vessel, ImpiFish (Facebook: Chris Bertish)

Bertish averaged close to 70 kilometres per day, largely travelling at night to avoid damaging sunlight.

"I don't consider this to be a SUP (Stand Up Paddle) adventure anymore," he said midway through the voyage.

It has become the ultimate waterman project, using all my knowledge from everything to do with my savings, my navigation, my surveying, my surfing and being comfortable in giant storms and big waves.

Dealing with everything you could possibly imagine and more, and still staying positive and proactive to get through it, one challenge at a time.

Bertish is not the first to have completed the solo voyage, beaten by 67-year-old Polish man Aleksander Doba who paddled a kayak across the Atlantic.

Hungarian Gabor Rakonczay traversed the expansive body of water in a canoe in 76 days in 2012. // ANTHONY PANCIA

© Australian Broadcasting Corporation. All rights reserved.