> Maybe some kind engineer or physics teacher can help me on this. I remember reading somewhere that a canoe is the most efficient boat design, the bicycle is the most efficient land transportation and the jet airliner is the most efficient means of air travel. All are based on people/miles for the least expenditure of energy, or something like that. Could this be true?

Firstly, I'd have to argue with that definition of the word "efficient." Compare a bicycle and a car, and set the distance at four hundred miles (roughly the commute from here to where I live in New York, for those who care). A bicycle may use less energy to cover the distance than a car does, but there is less of that energy available. I can't think of anyone who could bike the distance from here to there without replenishing his energy several times along the way (and that's even allowing that he could bike on the highway, which he cannot), but I can drive it on about two-thirds of a tank or gas.

Secondly, using the definition of "efficient" given in the example, I doubt that the canoe is really more efficient than the raft.

Thirdly, I doubt that the jet airliner is more efficient than the blimp.

Dar "And I don't mean the Goodyear blimp" ien