Great, I'm back in the car and am traveling. Will do the exercise once I'm back home.

Have you ever experienced pant buckles messing with the compass? I wonder about zippers.

Apart form that I do wear a roadid bracelet that has a small band of metal and a roadid dogtag that is metal as well.

I've not noticed interference from these things but will need to pay closer attention next time I do an exercise with the compass.

I've definitely noticed magnetic interference when working in or close to the car.

I've used excel enough to understand the basics and how to use macros, I'm computer savvy enough to figure things out. One would need to write down magnetic north bearings after every 50 feet or so with your method is that right? In any case I should do the exercises before moving on to the next step. Will check again here once I've arrived back in NY and have done the exercises. Thanks for doing this Gershon.

@Dryer, interesting about the boating (gps?) solution .