On Fri, 16 Apr 2010 10:24:10 -0700, "nom=de=plume"
wrote:

But wouldn't a boat of the size I mentioned be powered with a decent engine?
Seems like it would be, but I haven't really looked into it.

A 40 ft cruising sailboat would typically have a diesel in the 30 to
40 hp range. In flat water and no wind that's enough for 6 1/2 to 7
kts if the bottom is clean.