Compass 4-6400/360 MS

The Silva Compass 4-6400/360 MS is Silva's full-size baseplate compass, the model used by NATO forces, with a housing graduated in both mils (6400) and degrees (360). The Compass 4-6400/360 MS carries GPS positioning scales, a magnifying glass and rubber feet for precise map work, and its needle is balanced for the Magnetic South (MS) zone.

Who it's for

Navigators who work to a grid. Army and cadet training, search and rescue, rogaining and anyone who plots bearings in mils as well as degrees. It is the compass Silva build for soldiers and officers, and it suits the walker who wants more from a map than the next track junction: off-track routes in the Budawangs, the trackless tops of the Victorian Alps or a long day of bush navigation in Namadgi. Silva rate it for expert users, and it rewards the time you put into learning it.

Accuracy and features

The rotating housing is marked twice: 6400 mils around the outside for military-style bearings and 360 degrees on the inner ring for everyone else, so you can work in whichever system your map, your team or your instructor uses. The long baseplate carries scales for reading grid references straight off the map, which is how you pass a position to a GPS or a rescue team, and a built-in magnifier makes small contour lines and spot heights readable. The needle is balanced for the Magnetic South zone, so it swings level and reads cleanly across Australia and the rest of the southern hemisphere rather than dragging on the capsule.

Using it in the field

Lay it on the map and the rubber feet stop it sliding as you line up a bearing, even on a slick map case in the rain. Rotate the housing, turn the map and the compass together until the needle sits in the orienting arrow, and walk the line. The detachable lanyard keeps it round your neck or clipped to a pack strap between bearings.

Durability

Silva class the Compass 4-6400/360 as waterproof and back it with a five-year warranty, so it belongs in the chest pocket on the wet days when navigation matters most, not left in the car.