: I found this compass in the auto dept. at Walmart for $2.25. The ball section
: is 1 1/2" and the suctions cup holds it on. It also floats. The
: suction cup could be glued on and the compass pulled out of the cup and
: stored until it is to be used. It can be mounted in any direction.

You want to definitely avoid any compass made for automotive use. Their readings are backwards. Trying to use them in conjunction with a map and a handheld compass will send you off in the worng direction.

a handheld compass, and a proper nautical compass that is deck mounted, are designed to be read from the top, while automotive compasses are designed to be read from the back. While this makes sense for a car driver who has one of these things on his or her dash, and is not comparing it to another compass, the readings are opposite what you get with a "normal" compass.

let me elaborate. Suppose you are in, or next to, an automobile that is heading north. Since the manufacturers of these things assume that the compass will be mounted in front of the driver, the automotive compass will have a floating ball with the letter N on it, facing the driver. But to get this display, that N has to be on the SOUTH side of the compass. To make it more confusing, the letter on the NORTH side of the compass -- plainly visible through the front window of the car, or from above, is a big "S".

To make things even stranger, back-reading, automotive compasses, if you read them clock wise from above, should go N W S E, while handheld compasses would read N E S W.

As I look at the thing you have in your picture, it isn't even a proper auto compass. What the heck is it?

PGJ