Navigation Buying Guide

Compasses

Technology is advancing constantly, but some things haven't changed in a long time: compasses. Compasses are still on the top 10 list when it comes to essentials of wilderness travel and exploration. Compasses don't rely on batteries or other gear that can wear out. Being able to navigate with just a map and compass is an important skill for anyone, regardless of how often you trek into the wilderness. This is one tool that can save your life.

There are three types of compasses: accessory, basic and specialized.

Accessory compasses: These compasses are used as an accessory and are generally worn for fun or used as a quick reference. They are found on key rings, watches and in some jewelry. Accessory compasses are small, round compasses with no base plate. They behave just like any other compass and point accurately at magnetic north.

Basic compasses: Basic compasses are inexpensive, but they do quite well for use in wilderness travel. Basic compasses are often the compass for the beginning navigator, such as a Scout. They have all of the components a compass needs yet lack the extra features.

Specialized compasses: These are the compasses of serious navigators. They have all of the features of the basic compass, plus the extra features that are great for backcountry exploration and for those who are regulars to wilderness exploration and mapping. If you are a frequenter of off-trail exploration, spending the extra money on a specialized compass will be well worth it.

Compass component basics

The basic, or standard, features of a compass are:

• Magnetized needle: This is typically the red end of the compass needle. This end will point towards the strongest magnetic field: magnetic North Pole. The needle can be confused by other magnetic fields, such as those created by magnets, so it is best to leave those at home when you journey into the wilderness.
• Liquid-filled capsule: This is the housing, or dial, that contains the needle, its pivot, or bearing, and a dampening fluid. The dampening fluid is designed to protect the needle from jarring movements and to minimize the needle's movements while you're trying to obtain a reading.
• Rotating Azimuth Ring: This ring is also known as the bezel. It is a ring marked with degrees, from 0?-360?, usually in 2? increments. The degree marks circle the outer edge of the compass capsule. "Azimuth" is your direction of travel, in degrees, between two points. Azimuth and bearing mean the same thing.
• Base plate: The base plate is a rectangular base, usually made of transparent plastic, on which the capsule sits. Some compasses have rulers, in inches and centimeters, that are etched into the straight edges of the base plate. The ruler etches are helpful when you need to measure distances on topographic maps or charts.
• Orienting arrow and parallel Meridian lines: The orienting arrow is the opposite side of the magnetic arrow. It is usually white or black. The Meridian lines, also called North-South lines, together with the orienting arrow, help orient your travel on a map by aligning the Meridian lines on a topographical map. Fixed orienting arrows will require you to figure out the difference between true north and magnetic north.
• Index line: Also called the direction-of-travel line, this is located at one end of the base plate and can be used by the planner for practical navigating.

Specialized compass features

The added extras that make your compass more than a compass are:

• Declination adjustment: This is an orienting arrow with more sophistication. It can be aligned to reflect the magnetic declination in an area of travel. A tiny adjustment tool, usually attached to the lanyard, is used to turn a small screw on the compass housing. This adjusts the orienting arrow so that it is no longer parallel with the north-south lines; it will be offset by the difference which you put in with the dial. When the Meridian lines are lined up on a map, the adjusted arrow will accurately point toward magnetic north.
• Magnifying lens: A magnifying lens will be very helpful when you need to read the small symbols on the map. It is usually a small lens mounted into the base plate.
• Sighting mirror: This mirror serves as a personal mirror or a signaling mirror, and it also improves accuracy when gauging readings on distant landmarks.
• Luminescent indicators: These will be on your magnetic needle on both sides of the orienting arrow and can be on the azimuth ring at the four cardinal points. They are faintly illuminated for easier compass reading in dim light or on darker nights.
• Clinometer: The clinometer allows you to measure the angle of a slope. If you are climbing or hiking, then this will be helpful for assessing hazards, such as an avalanche. You can also gauge the height of objects.
• Lanyard: A lanyard is a piece of string or plastic that acts as a necklace or enables you to attach the compass to a belt or backpack.

Compass tips

To decide which compass is right for you, consider your off-trail skill level and frequency. If you are a beginner, then the best compass can be the basic compass. This compass is free from the extra gadgets that you may not understand or know how to use. A basic compass is also great for camping and outdoors, experienced day-hikers or recreational backpackers who stick to trails. They will do just fine with a basic, inexpensive compass.

If you are a fan of off-trail exploration and love to trek around the backcountry, look for a specialized compass with the extras you'll use. A specialized compass is great for explorers who've used and owned a compass before. The added extras on these compasses from our sports store are a good investment.

GPS Navigation

Global positioning systems, or GPS, pinpoint locations on the land and sea using a network of 24 orbiting satellites operated by the United States Department of Defense. They were originally intended to be used as a navigational aid to the United States military. The American satellites are operational data transmitters, sending waves of information to Earth. A GPS is a receiver that captures a combination of three or more satellite-transmitted waves. The captured waves from the satellites triangulate the GPS receiver's position. Under ideal conditions, a GPS navigation system can achieve position accuracy of better than three meters. That's pretty darn good whether you're hiking or planning automotive use for your GPS!

There are four basic functions that a GPS can perform:

• Giving a location: This is the whole point of a GPS navigation system (also known as a nav system): its ability to accurately triangulate your position based on the data transmissions from multiple satellites. It will give your location in coordinates, either latitude and longitude or Universal Transverse Mercators. (UTMs were developed by the military and are used to pinpoint a location on a map. Most topographical maps have UTM gridlines printed on them.)
• Point-to-point navigation: This feature allows you to add waypoints to your trips. By using a map, the coordinates of a trailhead or road or the point where you're standing, you can create a point-to-point route to the place where you're headed. You will have the trip mapped out including any stops you add in.
• Plot navigation: This allows you to combine multiple waypoints and move point-to-point. Once you reach the first waypoint, the GPS can automatically point you on your way to the next one. The waypoint-management software comes with most GPS systems for easy database management.
• Keeping track of your "track": This is one of the most useful functions of a GPS unit. You can map where you've already been. This virtual map is called a "track," and you can program the GPS to automatically drop "track-points" as you go, either over intervals of time or distance. This can be done on land or in a nautical setting, and allows you to retrace your steps.

GPS component basics

The basic components of your GPS are:

Screen: There are different screens available, each with its own menu. Color screens can be good in maritime environments where you need the individual "lumps" to be distinguishable between land mass and water depth. Grayscale screens are just fine for other outdoor needs. Large screens are perfect for navigation in a vehicle. The large screen is easier to see, but it could become a distraction to drivers. Illumination is another option. These can be read in a variety of light conditions and can light up for nighttime or low-light.

Antenna configuration: The different types of antennas have their pros and cons. Quad helix, or quadrifilar helix, antennas are the most common in newer models. They are considered the best for use under tree cover. Flat patch antennas are an inexpensive alternative to the quad helix antenna if you usually hike or travel in open country. Note: with a high-sensitivity processor chip, the performance of your GPS will be enhanced dramatically, regardless of the type of antenna you have.

Built-in antennas are less likely to break off or get damaged. External antennas are less protected, but can be repositioned and manipulated for a better signal. The optional plug-in antenna is great when you want to use your GPS in a car or boat, and it will allow you to pick up signals even if you are under a metal roof.

Internal maps: The amount of pre-loaded map information a GPS contains can really affect the price. Maps include a base-map of North America, backcountry details of major rivers or street-level road maps. There are also a limited number of international maps available.

Barometric altimeter: All GPS units can give elevation information, but not all of them come with a barometric altimeter. The barometric altimeter operates independently of the satellite signal, so even if you're hiking in a low signal area, and you lose the signal, you can still read an accurate elevation reading. The barometric altimeter runs off of air pressure, so it can also give you an idea of approaching weather conditions and changes by showing a graphic chart of barometric trends. With a little advanced warning, you can whip out a parka or pitch your tent.

Other GPS considerations

The other features and considerations you'll want to think about are:

Usability: Does the GPS give you a simulation mode where you can familiarize yourself with all of its functions, regardless of a signal? You'll want to be familiar with your GPS before you head out and explore.

Power supply: What kind of batteries does the GPS use? You'll want to know if the GPS will work with more than one type of battery and how many extra batteries you'll want to pack, just in case. Most modern GPS navigation systems have a built-in back-up battery that will keep your stored information safe even if the internal battery runs out.

Speed: How fast will the GPS system acquire the signal? Is it a constant speed? Some navigation systems process data and update much more quickly than other. Usually, the more channels a GPS system has, the faster it will compute and refresh the on-screen information. Look for "time to first fix," or TIFF data when researching different models.

Size: The smallest GPS systems available today are no bigger than a cell phone and can fit in the palm of your hand, but size affects price. The smaller GPS systems will have double-purpose buttons or have a higher price tag. The larger GPS systems have clearly labeled buttons, which makes using them and reading their labeled functions a lot easier.

Design: Look for a durable design. Can buttons stick easily, can parts break off if your kid puts it in his mouth and will the casings crack if they are dropped? Waterproof ratings are on most GPS systems and some will even float.

With this information, it should be less scary to wade through the possibilities when you're looking to buy any navigation systems, either a compass or a GPS navigation system.

Navigation terminology

• Bearing: This refers to the direction of travel and is usually expressed in degrees. Traditional bearings have been measured from the north or south points of a compass.
• Cardinal points: These are the four directions on a compass: North, South, East and West. The compass is sometimes called the compass rose.
• "Dip" zones: There are about five different magnetic dip zones. They can cause a compass needle to point up or down which will affect the accuracy of a bearing. All of the contiguous United States falls within the same magnetic dip zone.
• Magnetic declination: This is the angle, measured in degrees, between magnetic north and true North.
• Magnetic north: This is a point on the Earth's surface that "wanders." The Earth's magnetic field points vertically downwards.
• Quad helix: This antenna has a four spiral-blade configuration that is capable of a greater coverage.
• True North: This is the direction to the North Pole relative to your position.

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