>>The instrumentation that I use for testing is made up of a compass and speedometer and slip angle measurement. I also carry a windspeed instrument.


And I thought your were talking about gyroscopes, GPS units and stress sensors. Everybody carries a compass on board and speedometers are outdated. Just use a GPS unit with tracking ability and make sure there is no current on the body of water you're sailing on. Having a reference boat around with reference crew helps a lot as well.

Talking about GPS tracking here is one from my personal archive. Note how the top speed (30 km/u=16 knots) of the sloop rigged craft is reached on ALL courses !

But then again I'm not a real designer.

Wouter