[PCW] A question of weight

[Georgs Kolesnikovs]

>Your answer "at 16 knots the heavier boat would require more
>horsepower and burn more fuel" is a statement, not an explanation. I
>don't deny that it's right. Experience tells us so. But why?

Gary, sounds like you're after the kind of answer only a physics 
professor could provide. Perhaps these definitions of weight, mass, 
velocity et al might help:

http://www.av8n.com/physics/weight.htm
http://whatis.techtarget.com/definition/0,,sid9_gci552571,00.html

--Georgs