About 15 years ago, we were on holiday in Brittany & saw a chap riding a bike on a big, open beach: Attached to the handlebars, or frame, was a fairly small sail (8' tall?) like those on windsurfers.
The cyclist had one hand on the bars & the other "controlling" the sail.
He seemed to be struggling
Never did see whether he was making progress, as we were caught-up in traffic.
This was back in the days when I was surfing a waveski & we were contemplating trying an aerofoil kite attached to a ski, for flat days