Stephen Harding wrote:

Remember, the purpose of getting on an air machine has always been to
get somewhere, and typically, to *get somewhere quickly*. Not an
airship trait.

Why not commercial ground-effect vehicles (i.e: "Caspian Sea
Monsters") that theoretically could make transatlantic trips
at approximately .5 mach economically, safely and luxuriously?

http://www.att-nn.com/ENGL/MPE.htm