Compass Requirements - photographs and models included -- MUST READ INFO

All compasses have a magnetized needle that points north, and have a way to indicate direction of travel. Mountaineering requires a compass with additional qualities. Compasses that hang from parka zippers or hook on watchbands are not suitable for this course or as part of your ten essentials. Good compasses are easily found, but many compasses on the market are not suitable for use in this course.

Caution - when buying a compass

Every year, some students buy unsuitable compasses, usually the result of not following the guidelines below. Often, a sales person (who may or may not know the requirements of a good compass) was asked for advice. To complicate things further, our local outdoor stores sometimes run out of stock of the recommended compasses. Sales people will try to recommend alternatives (mostly unsuitable). They aren't malicious, but in fact are trying to be helpful. In reality, a good mountaineering compass has no substitute. Retailers will carry a variety of compasses, some suitable, some not.

Required Features

1.	Adjustable declination: A moveable orienting arrow, which provides a built-in declination adjustment. If there is one feature that simplifies map and compass work, this is it. Compasses with adjustable declination can often be identified by the presence of an adjustment screw on the back of the housing (on the underside of the compass, look at the bezel - the screw is usually brass or copper colored).
	•  All students MUST have a compass with adjustable declination. Be aware that compass descriptions in stores may not always be accurate. Be very sure to understand the requirements, not merely to read summary sheets. If you aren't sure, ask a salesperson to show you how to adjust the declination on a specific compass. •  If you already have a compass without adjustable declination, you may not use it in this course. Recent experience indicates that such compasses detract from the learning experience.
2.	A transparent rectangular base plate with a direction of travel arrow or a sighting mirror.
	•  Transparency allows map features to be seen underneath the compass. •  The rectangular shape provides straight edges and square angles for plotting and triangulating on the map.
3.	A bezel (the rotating housing) marked clockwise from 0 to 360 degrees in increments of two degrees or less. (Some compasses are numbered backwards, in a counterclockwise direction. These are not suitable for use in this course.) In general, bezels should be large to allow use while wearing gloves - the larger size also improves accuracy. Black bezels with sloping sides are preferred.
4.	Meridian lines: Marks on the bottom of the interior of the circular compass housing, marked with parallel 'meridian lines', which rotate with the bezel when it is turned. The meridian lines run parallel to the north-south axis of the bezel, however turned. Meridian lines are necessary for plotting and triangulating on the map.
5.	A ruler and/or gradient scale engraved on one of the straight edges, used for measuring distances.
6.	A 3 to 4-inch base plate. A longer straight edge makes map work easier.

Diagram of minimum features:

Additional recommendations

•	A sighting mirror in the cover: This reduces errors introduced when moving the compass from eye-level after sighting to waist-level for reading the dial.
•	A liquid-filled housing to reduce erratic needle movement (only needed on some compasses). In some cases, steadying the compass needle can be difficult.
•	An inclinometer: a gravity driven arrow that allows you to measure slope angle.
•	Note: Stay away from "quadrant-type" compasses marked from 0 to 90 degrees, 0 to 90, 0 to 90, 0 to 90, because they are difficult to use.

Diagram of recommendations:

Recommended compasses

Compasses must have the first 6 features listed, including a declination adjustment mechanism. Don’t buy a new compass without this declination adjustment feature. The declination adjustment can usually be identified by the presence of a small adjustment screw on the back of the bezel (on the underside of the compasss).

In recent years, manufacturing defects and quality issues have plagued many previously desirable models, including some from Suunto, Silva and Brunton. For that reason, we are recommending a specific compass as best, and another as 2nd best, although many others are suitalbe.

Recommended: Brunton 15TDCL Compass

This compass is the "First Choice" for use by students in the Mountaineers Basic Navigation course.

At about $65, the Brunton 15TDCL has adjustable declination accounts for difference between true and magnetic north; a lanyard key which locks adjusted declination into place; a sighting mirror with vee notch which allows quick bearing acquisition on landmarks and also folds down to protect the compass; an inclinometer to measure slope angles- useful to winter travelers to help estimate danger on avalanche-prone slopes.

We have also found that the quality control is good, and have seen few defective Brunton 15TDCL compasses, something which has been an issue with some other models (hence the "first choice" recommendation - this compass has both the features and the needed quality control).

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Second Choice: 

Suunto MC-2 Pro Compass

Price:  about $60.00   Adjustable declination accounts for difference between true and magnetic north; lanyard key locks adjusted declination into place - 2-zone geographical balancing system allows you to easily use compass in the northern and southern hemisphere (only important if you plan to travel to South America or other Southern Hemisphere destinations).

If you get this compass, open it up and try it in the store (with assistance from a staff member) and verify that the bezel turns smoothly, and that the needle isn't stuck. We've had a few problems with some of these compasses, while others have been fine.

Photographs of other acceptable compasses - we suggest you look at this link before buying a compass.

Unacceptable compasses

Compasses are unsuitable for mountaineering if they are too small for accurate bearings, do not have meridian lines, are numbered in 5 degree increments, have non-transparent housings, do not have degrees from 0 to 360, or cannot be used for measuring and plotting bearings on a map.

Features which make a compass undesirable or unsuitable:

• Lack of a straight edge for plotting lines on a map
• Lack of declination adjustment
• Lack of meridian lines inside the bezel
• Small size -- less than 3.5" x 2.2"
• Small bezel - less than 2" in diameter
• A dark base plate (you can't see a map through the compass)
• Poor action/movement (poor mechanics - should be smooth and firm, not loose)

UNSUITABLE compasses for this course:

• Brunton 26 DNL-CL
• Brunton model 8020 GPS
• Suunto KB20/360
• Suunto MB-6 Matchbox
• Brunton model 9020 G

Photographs of unacceptable compasses (many of which are commonly sold at local outdoor retailers) - we suggest you look at this link before buying a compass.