vortex

Finding a magnetic vortex is not so easy. Actually, there are many reasons. What we use is a cell sensor. Just when you are over a vortex the red light starts flashing and the alarm starts ringing. Maybe it is more on a BEEP noise. Still, it takes time to find a vortex and few are near. Often they are seen as a bare area. Great, like a bald spot in the green grass. Make sure that you affix a flag to that spot so you can find it again.