[gurps]_[VEHICLE]_of_the_week_632_-_Archvillain's_Yacht_(1920s_Version)

[Onno Meyer]

> Not with a length of 120 feet, it's not.  Speed of a displacement boat
> is limited to about 1.35 * sqrt (LWL).  (LWL is length on water line,
> typically less than overall length).   To go faster, you need to
> plane.  To plane 700 tonnes, you'd need quite a bit more power.

Speed   Minimum LWL
10      55
20      220 
30      494
40      878

Assuming that speed is in mph or knots and LWL is in feet, that 
doesn't feel right. Destroyers do 40 knots without the length of 
a cruise liner, but they don't look like planing hulls to me.

compare
http://en.wikipedia.org/wiki/G_and_H_class_destroyer

Onno