> I remember reading somewhere that a canoe is the most efficient boat design
>
> assuming propelled boat, yes, it is. . . the raft is not more efficient unless it's being propelled by a river. For example, it's easier to take a canoe upstream than to take a raft upstream.

Which is much of the reason why I was complaining about the definition of "efficient" that we were stuck to, here. According to the definition given, the raft would be more efficient.