(CNN) South African watersport pro Chris Bertish has just nailed a world first: he's crossed the Atlantic solo, unassisted and unsupported, on a stand-up paddle board.

Yes, that's one of those surfboard-like contraptions you've probably fallen off on vacation. And yes, we mean the real, genuinely-ferocious ocean that's claimed sailors' lives since man first decided to strap wooden planks together and take to the seas.

Chris Bertish.

The big-wave surfer and Guinness World Record holder crossed 4,500 nautical miles, setting off from Agadir, Morocco, on December 6 and arriving at English Harbour, Antigua, on the morning of March 9, local time.

Bertish's stand-up paddleboard (SUP) may not be an off-the shelf job -- it's a custom-made,1,360-pound, 20-foot-long vessel fitted with a tiny cabin and solar panels -- but that doesn't mean the journey was any less daunting.

For 93 days Bertish has paddled the equivalent of a marathon a day, skirting the Canary Islands before heading into the open ocean and aiming for the Caribbean. Along the way he also set the record for the furthest distance traveled solo, unsupported and unassisted over open ocean in a day (71.96 miles).

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