Compass
We use a Precision Navigation TCM2-50 3-axis Digital Compass. This compass provides a true magnetic heading as well as pitch and roll from an inclinometer that is accurate to a tenth of a degree from +/- 50 degrees.

We have been using a Precision Navigation compass for three years. Our first year we borrowed a TCM2-20 compass, which we accidentally destroyed the EPROM'S on and were forced to purchase a new compass. Our new compass is the TCM2-50 and has proved to be very resilient as it has survived operating completely submerged in water, and cleaned up with alcohol very well. Since then we have had no problems with this extraordinary compass.