Neat design, but I'm not sure how practical it'd be. It's going to be too slow for travellers but not big enough for the true leisure crowd. And that's the problem. On cruise ships and the like, they've got all sorts of things to keep folks busy because they've got space. On top of that, most cruise ships dock and let folks off to enjoy whatever they want.

This just doesn't make that easy. It could be done, I suppose, but I think it's a very niche market.

Looks damned cool, though. Like a giant sperm flying through the sky.

And to quote one commenter, "Japanese Research vessel off the port bow!"