Re: 3D Printing of Sailboats
"people have been able to buy 2-D printers for sometime now (both photocopiers and computer printers) and I don't think there are many people who are running a publishing company that way. "
It is called "demand printing" and if you order a title from Amazon and other sources, who are publishing it for an author, that's how they print it. Printing single copies of books to fill single orders may cost 5x-10x more than printing a conventional book on press, but it doesn't pay to publish books, stack them, stock them, warehouse and distribute them, until you get into tens of thousands in one press run. So even at 10x the cost, demand printing can be cheaper for small volumes.
The parallels between boat building and book publishing would seem to elude me, though.
I could see a swimming-pool sized vat of goo, topped off with a herd of high powered lasers, to stereolithographically produce boat hulls (with integral tanks and piping, etc.) or auto bodies or anything else of size, but the goo ain't cheap nor would the machine to work with it. Of course, the same thing ("ain't cheap") applied to the Indigo and Xerox machines that did "on demand' printing in the late 80's, and they still managed to find and take over a market niche. Emphasis on niche.
Then there's the question of whether any of the plastics or metals currently being used for 3D printing would be suitable for a yacht hull. And titanium gets crossed off the list immediately, because if you could afford that much titanium, you'd buy a Gulfstream instead of a cheap less-than-one-hundred-meter yacht.