Sharp rotor

What I didn’t mention is my long established belief that any sail or kite that is to be useful for modern shipping must have a L/D ratio of more than 4. Preferably more than 10 and then moving about.

This implies to a great deal that I believe kites like eg. Skysails are promoting are doomed to niche markets. And any successful ship AWE would probably be looking like a solid airfoil.

And also such a ship would need an efficient keel. I expect for such a large ship as a cargo ship we may be looking at many smaller keels so to keep the aspect ratio of the keel high without going monstrously deep. I am not sure how the rest of the hull though would interact with such keels.

In the end, maybe we dont need to think so much about the shape of the AWE or sail; it may already be unviable just looking at the keel/hull and practical water depth