There is also a thread on the YBW Forum in England about this incident -
Loss of Ocean rower-boat design https://forums.ybw.com/index.php?threads/loss-of-ocean-rower-boat-design.578037/
I wonder if Jean Jacques designed / built this boat himself?
If so, it probably would have been much easier / cheaper / safer in the long run to buy an existing second hand rowing boat - I think that there are probably quite a few out there always for sale.
The boats designed by Phil Morrison for the first Woodvale transatlantic rowing race in 1997 seem to be the most numerous -
Ocean Rowboats https://angusadventures.com/adventurer-handbook/oceanrowing/ocean-rowboats/
These boats are self righting - but only if the hatches in the cabins are closed, and if they have the emergency fresh water ballast in the keel.
Twenty odd years ago a pal of mine decided to have a go at the female singlehanded transatlantic rowing record - she used the boat that her Dad had rowed in the 1997 race from the Canaries to Barbados.
But she was maybe a bit too ruthless re her weight elimination, and / or maybe she had a hatch open - when she was about 10 days out she was capsized, and the boat stayed inverted.
She had to activate her EPIRB, and after about 8 hours sitting on top of the inverted boat, she was rescued by a cargo ship.
The boat meanwhile carried on drifting, upside down, across the Atlantic, and eventually washed ashore on an island in the Bahamas.
The Rannoch boats seem to be more popular now - but I am sure that they are a lot more expensive than the Woodvale boats were in kit form (many of the rowers in the Woodvale races built the boats themselves from kits).
https://www.rannochadventure.com/boats-2/rannoch-r10-solo