GURPS Spaceships Design Spreadsheet

[ericbsmith]

Originally Posted by vicky_molokh

Doesn't the ground effect increase efficiency of thrust relative to a 'naked' propeller, leaving more power available for horizontal thrust?

Also, ground speed three times higher than water speed, is that right?

The primary advantage of the ground effect skirt is to increase stability, which helicopters and VTOL Jets have issues with when they get close to the ground or water (the backblast off of the ground causes vortices which make it difficult to control). The Hovercraft speed record is only 85mph on water and 56mph on land (this is, literally, where I got the max speeds from for the Hovercraft in the Optional Rules page); hovercraft are never going to have speeds, or general stats, comparable to Helicopters.

Now, I'll have to look into the actual speeds listed, because I don't think that's right, especially with ground speed being greater than water speed.
Edit: And it looks like I accidently multiplied Hovercraft Ground Speed by x4 across the board (actually, in the formula I doubled it instead of halving it like Water Speed).