Anybody use a RAD gauge for tuning?

[thomas]

Was thinking about buying one to help me tune my boat under different conditions. Anybody have any experience with them? Where can I get one?

[Bill O'Neal]

I use a RAD guage to let me know what the relative air density is.

You can buy one from any speed shop (online) for about $80.00

[Roger Ramjet]

I use this weather station.

http://www.computechracing.com/drsystem.html