The experiment shows a handful of sand 20 cm high on one of the wooden
walkways of the beach. But we could make a 6 meter high dune, with the same angle
for stability...
Building
a sand bar 180 meters long and 6 meters tall, facing the laminar sea
wind, it would create locally a very smooth upward flow,
which would allow the paragliders (and "floater" hanggliders) with
expert pilots, to keep them flying over for hours, playing with the
wind, sand, and sea ... The utility would not be another, except
perhaps
constitute the balcony to the sea, carrying a few kilometers beyond the
horizon the tangent of the visual curvature of the earth...