[gurps] Ultra-Ships according to Vehicles

[Onno Meyer]

David replied to me:
> > With no hydrodynamics, the drag is 6,879 and the speed is
> > 26.6 * 2 (planing) * 1.1 (streamlining) = 58.5 mph.
> > With mediocre lines, the drag is 1376 and the speed is
> > 45.5 * 2 (planing) * 1.1 (streamlining) = 100 mph.
> > With average lines, the drag is 688 and the speed is
> > 57.3 * 2 (planing) * 1.1 (streamlining) = 126 mph.
> > With fine lines, the drag is 457 and the speed is
> > 67.7 * 1.1 (streamlining) = 72.3 mph.
> > With very fine lines, the drag is 344 and the speed is
> > 72.2 * 1.1 (streamlining) = 79.4 mph.
> 
> Any ship that goes much faster than its hull speed (which is about 1.3
> times the square root of the length in feet at water line, answer in
> knots) is going to be planing, even it's not a hull that's well suited
> for it.  In a non-planing hull, it's a lot more expensive to go a bit
> faster than in a planning hull, and it can be terrifyingly dangerous.

Fine or very fine lines are -2 to wMR, and average lines 
are -1. Not exactly terrifying danger, but a step in the 
right direction ... basically I can choose between -1 to
aMR or 25 mph less. Either way, there will be roughly 10
times the payload of my ducted fan flyer moving at 1/5th 
the speed for the same sticker price, so there is room 
in an universe for both.

An ekratoplan might have twice the payload of the ducted
fan flyer at 2/3th the speed, but it might be slightly 
more expensive. 

Onno