The maintenance costs on this would be enormous! I sail regular old boring wind powered boats, and I have to admit, if I could afford this I'd probably buy it!

The maintenance costs on this would be enormous! I sail regular old boring wind powered boats, and I have to admit, if I could afford this I'd probably buy it! Saying that though, I have no idea how it would work legally in ports. I'm guessing you'd have to stay on surface in most territorial waters without some kind of crazy custom private clearance. I live in Australia and I don't reckon authorities would be very happy if you decided to submerge in the middle of Sydney Harbour!