[PCW] A question of weight

[Gary Stavrou]

Thank you for your replies.
Mostly they didn't address the issue.
My simple question is:
Two similar 45 foot displacement cats of different weights traveling  
at 16 knots.
Why does the heavier one need more power?
The best answer so far, I think, is that the heavier boat, making a  
bigger "hole" in the water has to push aside more water as it  
travels. But is the increased HP requirement proportional to weight?
Will a cat weighing 50% more require 50% more horsepower?
I don't think so. Perhaps in a barge it might, with all that frontal  
area.
But a heavy cat can still have fine bows.
There will be either a little more width or depth in the hulls.

Gary