And YC would be betting that their experience counts for something beyond just a random person with a weekly idea:
"We are hardware engineers with over two decades of experience between us, working at Tesla, SpaceX, JPL, Relativity, and some startups."
The experience you listed read more like name-dropping PR to sell this whole thing to other investors down the line.
Will there be a keel or any other foils to help create lift to not just get blown sideways?
To me this seems like solar roofs on electric cars. An obviously good idea that doesn’t really have a meaningful benefit.
The various supplemental sail technologies being tried to improve merchant shipping fuel efficiency are mostly only effective going downwind. They have to make serious design compromises compared to a dedicated sailing rig in order to meet cost and space constraints. But with the cost of fossil fuels expected to continue increasing (eventually including perhaps some sort of carbon tax or emissions cap) even a minor increase in efficiency is worth pursuing.
My guess is that some sort of deployable kite sail will eventually win out instead of this wingsail concept. We'll probably start to see that integrated into new ship designs as the cost is pretty low and the equipment occupies a fairly small volume at the bow.