The compass is the easiest navigation instrument to make yourself.

All you need is a good sized sewing needle, a magnet, a cork and a bowl with water in it.

Gently stroke the needle with one pole (end) of the magnet. Make sure you do this in only one direction, from the thick to the thin end of the needle.

Do this about 30 times, or a few more if it doesn't work!

Put the cork in the bowl of water (make sure there's enough water for the cork to float.) Balance the needle on the cork.

The cork and needle should then swing round to point to magnetic north.

Congratulations, you've just made a simple compass!