When do you need it:

We used this compass in a scouting game for the kids to find the next station. 

What you need:

• something that floats on water and can support the weight of a needle, for instance cork from a wine bottle
• needle
• magnet
• water
• a bowl or better the 3D printed version

How to compass:

• cut a small disk from the wine cork
• Rub the tip of a sewing needle against a magnet, making all your strokes in the same direction. Any magnet will do, but the stronger it is, the better. With a strong magnet, you may only need to make a few strokes with the needle. If all you’ve got is a standard refrigerator magnet, rub the tip of the needle against it up to 50 times. Your needle is now magnetized. 
• Push the needle through the edge of your cork disk and through the other side. You may want to use a pair of pliers for this part.
• Fill the bowl with water and put the floating cork inside. The side you rubbed against the magnet should points north

Printing:

• Scaled down to 40%
• 

You can also find the 3mf. File with the added color change.