Product Description

This is a magnetic compass with a sighting mirror and vee notch cover which snaps down over the capsule. The needle is in a liquid filled capsule and painted red (which points to magnetic north) and white. There is a luminous strip on the red portion of the needle. The capsule has the standard red "shed" arrow between two luminous strips for easier alignment in the dark, and parallel meridian lines running north-south. Declination can be keyed into the back of the bezel using a small supplied screwdriver (which fits on the lanyard). The south end of the compass arrow has a small index mark to align with a built-in declination scale. This same declination scale allows the compass to be used as a clinometer with the aid of a freely rotating black arrow which is attached to the same pivot point as the magnetic needle. The bezel has letters for the cardinal directions, written bearings every 20 degrees, major marks every 10 degrees and minor marks in 2 degree increments.

The short edge and interior of the baseplate has 1:24000, 1:25000, and 1:50000 scales in black and red for easier reading. The longer edges have two rulers: one in millimeters and the other in 1/20 inch graduations. Both the front and back bearings are marked with luminous strips, and three silicone feet are on the reverse of the baseplate. There is a hole in the baseplate for the attachment of the included red lanyard. The lanyard's length can be adjusted with a black slider.

Field Information

My Silva Ranger has accompanied me on backpacking trips in Zion National Park, the northern portions of the Sierra Nevada, the Santa Ynez mountains on the California coast and Santa Cruz mountains. Elevations have ranged from sea level up to 10,000 ft (3000 m) and temperatures in the general range of 40 to 100 degrees F (5 to 40 degrees C) with occasional extremes to 20 and 110 degrees F (-5 and 45 degrees C). Precipitation has included heavy rain, snow and hail.

Maintenance and Durability

I have not performed any particular maintenance on the compass – only splashing water on it when muddy or shaking it dry when wet. The bezel action is still smooth and the hinge and clip behave no differently than when I purchased it. The small included screwdriver used for setting declination has been used for a number of odd tasks (eyeglass repair, cleaning nails ... oh and setting declination) and hasn't shown any wear and has NEVER bent. This surprised me, as it seemed flimsy but is actually very durable.

The least durable element of the compass seems to be the red paint on the back of the baseplate. I have almost worn the Silva logo off completely. Additionally, the rulers have lost part of their tick marks where my fingers wrap around to the back of the baseplate when opening the compass. The compass can be opened more easily by lifting up on the tab of the sighting notch, but I often lift the cover from the sides. The black paint shows no signs of wear.

A close up of the baseplate with the points of wear circled. The metric ruler (on the other side) shows similar wear.

The silicone feet have yellowed slightly from being placed close to my iodine bottle. This has not affected how they feel or behave in any way.

Additional Remarks

There is not an unused feature on this compass.

I have found the "normal" compass action as good as I expect. The bezel turns smoothly, but not without me intending it to turn. It is slightly harder for me to turn it with one finger, but with the baseplate gripped between my index and middle fingers, I can easily and smoothly take or find a bearing. With the compass sitting on a map, the silicone feet allow me to apply a slight downward force so that I can easily turn the bezel with two fingers.

The red-shed is easy to find in sunlight or darkness thanks to a tick at the point of the arrow and luminous strips on both the needle and sides of the shed. The needle quickly settles and front and back bearing ticks are easy enough to read – however, I would prefer a slightly longer front bearing tick.

Declination is easy to set there are declination graduations on the interior of the compass (which are also used for the clinometer). I have threaded the included slide-lock to keeps the screwdriver on the portion of the lanyard behind my neck. I use the slide-lock to easily adjust the lanyard to different lengths throughout the day, depending on my needs.

Here you can see the declination screw and screwdriver. The declination is set to 17 degrees East.

The cover gives a positive snap when closing or opening the compass, but is never difficult to open. The hinge is stiff so that it only budges with a stern shaking but the entire range of motion is smooth. The hinge itself is well reinforced so I that I am very confident all parts are as square as intended. Unlike some compasses I have used, when the mirror is 45 degrees to the baseplate, the notch is perfectly vertical. This makes it easy for me to project my bearing to a distant object. A line which runs down the mirror and a small luminous dot below the notch helps square up the sighting notch.

The map scales get little use from me, but I have used them on occasion. I have found the rulers quite handy to measure the unmeasured such as map distances or litter and duff depths during field season.

I don't need the clinometer very often but when I do, there is little substitute. I have found that the large size of the compass makes it much easier to sight along the baseplate. The mirror ensures a more accurate read as I can sight the object and read the angle at the same time. I have used the clinometer to estimate tree hight, and ground slope – usually for the unplanned recording of field notes.

The clinometer in action, measuring the steep angle of this gray binder. It reads - 70 degrees in the mirror.

I specifically purchased this compass for an eight week forestry program, in the Plumas National Forest. I primarily used the Silva Ranger for direction finding and taking field bearings. Almost everyday for 8 weeks I had the Ranger tied to my belt or around my neck. One example stands out in particular – I had to establish 30 inventory plots ten chains apart (660 ft, 200 m) in a dense mixed-conifer forest over the course of four days. Due to the density of the forest and the steepness of the terrain, I had to read a bearing off the Ranger over 200 times a day! This is when I really appreciated the large size and mirrored sighting system – had I been off a small amount, I could have ended up on the wrong side of several large trees, and correcting for this would have been unnecessarily difficult. I worked with other people who would choose to consult the Ranger over their compasses (primarily Silvas and Bruntons with less features than the Silva Ranger).

I still use this compass for my forestry field work, in many of the capacities I described above. Most of my fieldwork requires the use of a GPS unit, and this compass makes an excellent compliment to those models without a build in compass, or if the unit or batteries fail. All-in-all, I am very happy with this compass and use it often. The only drawback is size and weight compared to other models of compasses. I need the various features of the Silva Ranger so often that this is the compass I bring on both my private and professional adventures. Did I mention that the hinge doesn't squeak? Terrific.