On Fri, 28 Aug 2009 20:20:26 +0100, Cherry Chapstick
wrote:

Ships use so much more fuel per passenger mile that they just don't come
into the equation.

cite, please

http://en.wikipedia.org/wiki/Fuel_ef...transportation

Spacecraft are potentially the most fuel-efficient mode of transport
in terms of passenger-miles per gallon of fuel.

--
Cynic