What hemisphere is this compass for? As far as I can tell it doesn't specify. Thank you — 4 Answers

The earth’s Magnetic “Pole” is in the Northern Hemisphere and is located above the Arctic Circle, approximately due north of Finland. It is not the same as the “axial North Pole” where Santa Claus lives. No matter where you go on earth, on the air, on the sea and on it under the ground, unless distracted my naturally occurring ferrous/iron deposits, large masses if iron/steel, or a magnet of any strength near the compass, northern or southern hemisphere, your compass needle will always point to the Magnetic Pole. Your physical location, east to west, and north to south, causes a feature called “Magnetic Declination.” On your topo map, you will find a North-indicating arrow for orienting the map towards the north. Near that arrow you will find the number if degrees, either west or east, that you must add to or subtract to the Magnetic Azimuth/Heading/Bearing indicated by a steady needle in your compass. This amounts to a “required offset adjustment - which you should not in the track mine on your map each time you stop and take a sighting for course correction to your objective point of march. In short, your lensiatic compass works anywhere you can take it. Just be outside and away from powerlines (electrical induction deflection if the needle), railroad tracks (massive it in needle attraction / deflection, and things like tracked vehicles, shios, aircraft, buried unexploded artillery shells, snipers...I digress.

Some lensatic compasses can be used in both the Northern and Southern Hemispheres. For example, the Cammenga Lensatic Tritium Compass can be used in both hemispheres because of the deep well that houses the needle.

Old Jarhead clearly hasn't heard of isoclinic lines that affect the north seeking arrow differtly in the northern and southern hemisphere. Due to the shape of earths magnetic field, a non compensated compass will have a north seeking arrow that tilts towards the ground in the northern hemisphere, but towards the sky in the southern hemisphere. All modern compasses come weighted to adjust for the arc of the magnetic field. If a compass made for the northern hemisphere is taken to the southern hemisphere, the north seeking arrow will likely drag on the lens, if you hold the compass parallel to the ground. You would have the same but opposite problem the going from south to north. There are compasses out there that are able to be used in both north and south hemispheres, but this isn't one of them. Cammenga sells these with the hemisphere option for a reason. Zac's question is a valid question, and should be addressed and clarified by opticsplanet.