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Recommended handheld GPS units

If you are just finding this post, you may wish to review the previous posts on what GPS is and some of the most common features to consider when thinking of buying a handheld GPS.

When it comes to rating, Garmin handheld GPS units consistently rank highly among users, and they have a wide range of models and prices.

For the price, the Garmin eTrex Venture HC GPS Receiver is well recommended. This unit retails for around $100, so it is not the least expensive model, but comes with enough features to make spending a little bit more worth it.

Garmin eTrex Venture HC

The screen is 1.3 x 1.7 inches and is color. The unit weighs 5.5 ounces so it is not too taxing to carry, and runs on 2 AA batteries. The battery life is rated at 14 hours of use; not too bad. It is waterproof, and has a 24 MB built-in memory. It can store 500 waypoints, and 50 routes, plenty enough for the average user.

Reviewers report that this unit can hold its satellite signal even with tree and cloud coverage, an important feature for many hikers. And it easily connects to your computer for transferring data, including additional detailed maps. The additional map sets are not inexpensive, however, but I have found them to be very useful for trekking in the wild.

It does not have a digital compass, but will show the direction you need to travel to the next waypoint as an arrow on a compass dial only when you are moving.

If you are a bit more adventurous (and willing to spend more) the Garmin Oregon 200 may be for you. This model retails for $230-370, and has a lot more features to play with.

Garmin Oregon 200

It has a large (1.5 x 2.5 inch) color, touch screen. Since the controls are on the touch screen, the buttons can be larger and easier to see than non-touch screen models. However, touch screens can take a bit to get used to.

View of the Oregon 200 touch screen

It is waterproof, and heavier than the Venture model, weighing in at 6.8 ounces. The Oregon battery life runs 16 hours on 2 AAs. Like the Venture, the Oregon has 24 MB of built-in memory, but unlike it, the Oregon accepts microSD cards, increasing your memory capacity many times. Also unlike the Venture, the Oregon’s built in map has topography detail.

One reviewer mentioned the weight of the Oregon as being noticeable, but the case is built ruggedly and seems substantial.

Looking for a few more features? The Oregon 400 series features units that are set up for specific outdoor activities like the 400c that focuses on coastal waterways, the 400i that focuses on inland waterways, and the 400t that is for hiking and biking. You pay more for this series as they include more maps pre-installed. Near as I can tell the maps are comparable with the 1:100,000 scale topographic series, and so they may not be detailed enough for the very serious hiker. I think I would save the money and use the price difference to purchase better quality 1:24,000 scale maps, for example, but if you don’t need that much map detail, the 400 series might be the way to go.

The Garmin Oregon 450 series is the next step up in memory and features. There is an Oregon 300 series, but for the same price range they have the 450 series, with more memory and a tilt compensating compass. The 550 series includes a digital camera with the unit so you can take georeferenced pictures.

At this time, the “sweet spot” for features and price for the average or even advanced user seems to balance around the Oregon 200 or 450. The eTrex is also recommended for those on more of a budget. These handheld GPS units balance the considerations of cost verses features well and offer two different price points for you to consider.

The large consume the small

It is an interesting paradox of the natural world that some of the largest species alive survive by eating some of the smallest species.

Consider the largest animal ever known to have existed. No, it is not a dinosaur, but an animal alive today, the blue whale, Balaenoptera musculus. This behemoth can grow to over 100 feet long and weigh 380,000 pounds. And yet, this animal does not eat large fish, but tiny planktonic animals, those that float in the water.

The blue whale belongs to the suborder of baleen whales, or mysticets, that all make their living by filter feeding plankton—sucking water into their mouths and trapping the small, floating plankton to swallow. The toothed whales, or odontocets, do eat larger prey.

There are several other large vertebrate groups that also specialize in eating the very small, and they too grow to very large proportions. For example, the whale shark (Rhincodon typus), the largest living fish at about 40 feet long and weighing in at 47,000 pounds. And then there is the second largest fish, the basking shark (Cetorhinus maximus), also a filter feeder. Giant rays also feed this way.

Whale shark, the world's largest living fish

So clearly, you can get very big eating small things. However, there has been a bit of a mystery in the fossil record. There has been a general lack of known filter feeding animals from the fossil record during the Mesozoic, the time of dinosaurs; clearly, that was a period in Earth’s history when things could get very large. So, where were the filter feeders?

An important piece of this puzzle has just fallen into place. Just published in Science is a paper outlining new discoveries of filter feeding fishes from the Mesozoic, and it turns out that they too were large (Friedman et al., 2010).

The fossils were mostly already in the collections of museums, having been collected in both Europe and North America. However, they were not well understood until this team began to look at them in more detail, and recognized their filter feeding adaptations. The fossils reported belong to the extinct pachycormid family, and include the new genus Bonnerichthys, named for the Bonner family of Kansas.

And in keeping with a theme, the pachycormid family of fish included the largest bony fish known, Leedsichthys, reaching over 30 feet in length in the Jurassic of Europe.

Leedsichthys, the largest spcies of fossil fish

This latest work shows that in fact there were a number of filter feeding fish through about the last 100 million years of the Mesozoic, filling this lucrative niche held in modern times by rays, sharks, and whales. Another mystery from the past is closer to being solved.

FRIEDMAN, M., K. SHIMADA, L. MARTIN, M. J. EVERHART, J. LISTON, A. MALTESE, AND M. TRIEBOLD. 2010. 100-million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas. Science, 327:990-993.

Many other interesting facts can be found here at Boneblogger. Look around and enjoy.

Basic features in a handheld GPS

In the basic post on GPS, we explored what GPS was and urged that you consider your needs for a handheld GPS before buying one. There are many features available on the various models out there, and there may be some features you would like, and likely some you would never use.

Screens

But before we get into the more exotic features, let’s look at the basics. One of the most important and basic features of any GPS is its screen. The screens on handheld units are basically of two flavors—monochrome and full color. As you would expect, the color screens are a premium feature and add to the cost. Screen size is also a significant consideration. A small screen can be very hard to see, and even if it looks OK in a store, taking it out into bright sunlight can really change a screen’s visibility.

Unit Size

Overall size and weight of the GPS unit are also something to consider. If you are planning to carry the unit around on hikes, small is definitely better. If it is so large and heavy that it gets left behind, it does you little good. It might not seem like it, but every ounce counts when lugging it around all day. On the other hand, if you are mounting it to your bike or boat, or driving into remote areas, its overall size might be less of a limiting factor.

Data handling

Be sure to review the unit’s ability to store waypoints and routes. A waypoint is simply the coordinates of any point you would like to reference again. For example, you might want to mark your car, camp, or house as a waypoint. It is fun when you are out in the boonies to see the direction and distance back to the house (“Look, we are 454 miles from home!”). Most units allow you to store several hundred to a thousand or more points.

A route is a series of connected waypoints that moves you from a beginning point to a destination. For example, on a hike you might start at the trail head, travel to a junction with another trail, take the right fork, and end at your camp. The route on the GPS will direct you from point to point as you go.

Some GPS units will allow you to save tracks. This is like leaving digital breadcrumbs. As you travel, the unit will mark your path along the way, showing where you have been.

Some of the GPS units allow you to connect them to a computer and move information back and forth between them. This is really handy in a number of ways. You could plan your route at home on the computer, upload the route to the GPS and let it take you on your way. Or, you might like to wander off and blaze your own trail, then download the track record to your computer to save a record of where you went.

Another important information-sharing feature is being able to upload additional maps into the handheld GPS unit. Most come with pre-installed maps, but depending on the unit, its maps might be more appropriate for a day hiking the golf course than trekking through seldom-explored wilderness. You can purchase software and map sets to load into your GPS so you could have full map details of the region you are planning to visit while in the field. You can also get free maps for Garmin GPS units at GPSFileDepot.

Weather resistance

Units might be billed as water proof or water resistant. Water resistant means that the unit can handle being splashed with water. Water proof means the unit can take being fully submerged in the creek or lake. Clearly, if you are going to be out in inclement weather, water proof is going to be an important feature. However, water proof does not mean you should plan to swim with it.

Signal receiving

Units vary as to how well they can receive the signals from the satellites. More expensive models often feature better signal capabilities that allows them to provide your location through trees and other sky-coverage. If you are going to be using your unit to travel in remote regions, make sure to get a high sensitivity receiver. You can also explore getting one with Wide Area Augmentation System (WAAS). This system supplements the standard GPS satellite system and provides for increased accuracy. It is not available everywhere, but if the unit you have is capable of receiving the WAAS signals, it will at no extra cost, and will increase the accuracy of your locations up to five times.

Battery life

Finally, you might consider battery life and type. Most units run on disposable batteries, typically AA, but they do not all consume batteries at the same rate. Some units have AC adapters, and some do not. Some have an internal rechargeable battery. Each style has trade offs. For example the disposable battery option might be fine for use a few times a year, but if you are a regular adventurer, you could spend a lot of money on batteries in a season.

Those are some of the basic features to consider. In future posts we will look at some of the fancier features, and investigate specific models.

Handheld GPS basics

So, you have heard about this GPS stuff, and are maybe considering buying one because they sound really nifty, and they are. But, maybe you don’t know very much about them, and all of the choices and techno-babble are just confusing. Never fear—we will break it down here.

GPS, or global positioning system, was made possible by the installation of 24 Navigation Satellite Timing and Ranging (NAVSTAR) satellites above the Earth. Each satellite transmits a signal back to Earth. On the ground, a receiver can pick up this signal and by a process of triangulation, getting a signal from several satellites at a time. A computer chip in the receiver calculates its location on the Earth.

This technology is useful for numerous applications: from guiding missiles to far-flung targets, to finding your way back to your car after a hike. The civilian applications of this technology have rapidly grown in the last few years, making a handheld GPS an almost-essential piece of equipment for outdoor adventurers (like bone hunters).

What are some of the considerations you might make when considering which model to purchase? First, think about your uses for a GPS. Are you only going to use it when driving to a friend’s house you don’t visit often; do you want to mount it on your mountain bike and track your progress over rough terrain; are you a hiker or runner and want to track your distances and speed; are your going to use it to find your way back to camp when you have wondered off during a day hunting or to get back to the clubhouse after a day of golf; or do you need one in your canoe so you don’t get lost paddling around the Everglades?

There are many features that you can get, and perhaps many that you will not use, so there is no sense paying more than you need to for your purpose.

For example, many newer cell phones have a GPS built in (in fact, all of them do to an extent; if you dial 911 the phone can transmit your location to rescue workers). You may be able to contact your cell service provider and just turn on the GPS mapping and tracking capabilities you already have. For example, Verizon offers this service for a monthly fee, and you can turn it on and off on a whim.

However, if your usage of a GPS is going to be very rugged at all, you likely want a unit that is designed with this as its primary function. Most units are at least water resistant, and some are water proof—a handy feature in boating, hunting, and fishing, applications. Additional features you can find on them include: barometric altimeter; electronic compass; heart rate monitor; two-way radios; ability to communicate with your computer to download and upload information; monochrome or color screens; and cameras.

Which one is right for you all depends on you. In future posts we will further explore their features and see some of the different models.

Formations

The crust of the Earth is composed of a complex mix of rock types formed in specific depositional environments. Most of your everyday experience occurs in erosional environments, places where the surface of the Earth is being eroded away by physical or chemical processes. Rocks underfoot are being broken up then transported as sediments to other areas. The Grand Canyon is a good example of a river cutting through the layers of rock, exposing those layers, and transporting the rock away—piece by piece.

A cross section model of the Grand Canyon showing the rock layers and how they are broken into recognized formations.

Where is that material going? It is transported to places where it is deposited, depositional environments, where the sediments accumulate. Given enough time and protection from further weathering, those newly deposited sediments can become the sedimentary rocks of the future. The deposition of sediment occurs in a wide variety of environments such as in oceans, rivers, ponds and the like.

If we look at the rocks on the surface of the Earth today, we can see differences in their color, texture, composition, and so on. We see layering as one rock type gives way to another. Geologists map these layers to trace out the history of the Earth, as each change in rock type represents a change in the environment that created it. So each outcropping of rock represents a time machine of sorts, transporting us back to the primeval environment of that spot.

A geologic formation is a formal unit, technically called a lithostratographic unit. That fancy word simply means that rocks are grouped by similar lithology, or rock type. For example, during the Late Cretaceous the last inland sea across the mid-continent of North America (a specific environment) deposited thick accumulations of chalk and shale. Today, we can lump specific sections of that collection of rock (lithology) into a single formation and call it the Niobrara Formation.

Each formation is described and named in a specific, formal way. There are rules that geologists should follow in designating specific formations (North American Commission on Stratigraphic Nomenclature, 2005). For example, each formation should have a type section designed. This type section is not unlike a type specimen mentioned in another post: it represents the standard for that formation to help others understand how it is unique.

In future posts we will explore more aspects of formations.

NORTH AMERICAN COMMISSION ON STRATIGRAPHIC NOMENCLATURE. 2005. North American Stratigraphic Code. American Association of Petroleum Geologists Bulletin, 89(11):1547-1591.

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