I was reading the board lifting out of the water thread and it reminded me of this
this is what AHD say:
The AFS-1 board This board has a « window-opening » in the nose. This will allow researching a maximum foiling speed without letting the wind put you out of balance during the flight. Built in Full K Carbon Length: 238cm Width: 67cm Volume: 112 litres Weight: 6.5 kg.