Bluebird, 1939, radical new twin keel design.
OK, so 70 years later, like the secret power source of Atlantis, the modern world has lost all knowledge of why this is a better design, and it has disappeared from the face of the earth?
I don't say the mass market is always right, just that when something becomes THAT SCARCE there is usually a good reason it failed to take the world by storm. Or stealth.
In the 80's didn't they promise us the Scheel Keel would dominate the world within ten years? Did anyone count to ten yet?