As it is with notebook computers, GPS receivers continue to evolve into faster, smaller and more powerful devices. Our latest crop of test models includes the brand new Model 11 from Apelco, the ColorTrak from Magellan, and from Garmin, the Model 48 and GPS III. We also have an update on the Magellan 6000 chartplotter, reviewed last April but now with 12-channel parallel tracking.
Clearly, there is a trend to more screen views, data display choices and features to the point of overload. Sensing this, some makers have designed their models to allow customization for only the information and screens a user selects. The inclusion of built-in database information at low price points is a big plus-the Garmin 48 with its database of city locations and nautical navaids is a prime example. Waterproof models are now the norm. Intuitive use has improved over previous models, but they still require study to fully tap their capabilities. Built-in simulation modes for most models (except the Apelco) allow for practice without having to go outside to acquire a satellite lock, so you can learn at home.
Accuracy has been enhanced through the development of 12 parallel channel satellite tracking, which enables the receiver to simultaneously use all satellites in view to yield a more accurate fix. A cute term for this is position overdetermination. This technology enables significantly faster acquisition and position updates, as well as more dependable coverage when there may be partial sky obstructions such as buildings, hills or trees. A position-averaging function eliminates the likelihood of extreme tolerance values. Because the GPS signal output from a satellite 11,000 miles in space is less than 50 watts, there is not much left of it when it reaches your antenna, so operation inside a boat cabin becomes problematical without a detachable antenna. Consequently, we consider this an important feature.
As long as the government employs Selective Availability (SA) to purposely degrade the signal from its true capability, the current accuracy guarantee is only about 100 meters or better for 95% of the time. In reality, accuracy in the neighborhood of 50 meters is quite common. The good news is that the White House has announced that SA will be turned off. The bad news is that it may not happen before 2006. Without SA, you could expect accuracy on the order of 15 to 25 meters, depending on the unit.
What do you do if you want greater accuracy now? This is where differential GPS comes in, but at quite a premium in cost and complexity. All the receivers in this test are capable of receiving differential signals, but to do so they need to be connected to an add-in box via an optional data cable. The lowest cost differential receiver costs about $438 over and above the GPS unit itself. Some GPS units have differential built-in, but not any of the handheld models. With differential, accuracy of 1 to 5 meters is possible as well as speed to .1 knot, 95% of the time. The Coast Guard quotes at least 10-meter accuracy 99.7% of the time.
Does it Compute?
All our test units can connect to a personal computer via a serial port and optional cable to a proprietary connector on the GPS unit. Garmin, Magellan and others have their own versions of software available for use with their units. There is a substantial and growing amount of third party software that will work as well. A PC connection lets you upload, download, store and export waypoint and route information. This is a lot faster than manual input of waypoint names and descriptions via the rocker switches common to all of these units. While current Garmin software doesn’t provide for a moving map display, this function is planned for the next release. The Magellan software already has this capability.
Third party map software vendors such as DeLorme, Microsoft and others have GPS connectivity built in to their latest versions. There is also a very active newsgroup on the Internet where a number of free or low cost GPS mapping and tracking programs are available. One caution, if you use third party software, is the compatibility issue. There are several protocols for the GPS to communicate with the computer, e.g., NMEA 183, 182. Not all map programs support all protocols. Before you select a map program, make sure your GPS protocol is included in the program.
What We Looked For
Initialization. Starting your GPS for the first time, or after moving it several hundred miles while its turned off, means the receiver has to figure out where on earth it is when you fire it up. The manufacturers take different approaches to solving this problem, and we note the easiest and fastest.
Time To First Fix (TTFF). Like initialization, this is also an improving area, owing to 12-channel reception and software refinements. For our evaluation, we defined TTFF as the time it takes from when the unit is turned on to when you actually receive a usable position. No one wants to wait for a sluggish lock-on, so we consider this an important element. This is especially true with handheld units with limited battery power, which are often turned off to save juice. Of course, all have an external power connection, but an external source is not always handy. We noted both cold- and warm-start times (see table); a warm start, for our test, meant the unit had been previously locked on to a fix within an hour).
User Friendliness. This is an arguably subjective term, but nevertheless an important characteristic with these increasingly complex units, and we kept sailors in mind when we made our observations. There appears to be a never-ending effort by software engineers to make any device more feature rich, often at the expense of simplicity. The chipmakers oblige by making more powerful and memory-rich processors. The manufacturers definitely have different approaches, and there are some notable differences in the software.
Features. These units all have an impressive array of features, but not all are easily accessed or particularly important to navigators. Some allow more customization than others of displayed data as well as screens available. There are lots of choices, and only you know what you want, but we can help you by pointing out the pluses and minuses as we see them.
What We Found
The evaluation units fall into four distinct categories. The Apelco is the lowest cost, simplest unit. The Magellan ColorTrak and Garmin 48 are price and function competitors and marine-oriented. We actively compare them in the individual evaluations. The Garmin GPS III occupies a unique niche with a built-in road map database of the Americas. The Magellan 6000 represents the latest merging of a GPS unit and chartplotter in a handheld device. Unlike their predecessors, all these units were easy to initialize, with warm and cold starts quickly accomplished.
What They All Had
Common to all units was an averaging function, which improves waypoint accuracy. With the exception of the Apelco, all are true 12 parallel channel units. The Apelco parallel tracks eight satellites and predicts the next four. All have a man-overboard marking function. All except the Apelco have a track-back function that allows a route reversal without manually marking waypoints. This is done via electronic breadcrumbs dropped along a route as the unit tracks where it is.
All units except Apelco have both a compass page (a simulated compass rose with compass needle) as well as a highway page (a plan view showing the route) for navigation. The Apelco has only a highway-like page. The Magellan 6000 had a full-fledged map page in lieu of a highway page. All models except Apelco let you select autovariation or true, whereas the Apelco has selectable true or manual input of magnetic variation. All models have a plot mode with variable zoom ranges, in which you can watch yourself move on the screen via an electronic track line. All have selectable distance units such as feet/meters, or nautical/statute/metric. All but the Apelco allow the map page to be oriented north up, track up (direction of current travel), or DTK up (desired track up to stay on course). All units took several seconds to display position updates, but the electronic updates were being logged at one per second.
No unit except the Magellan 6000 was very accurate in altitude during the adverse reception condition test. The published altitude margin is 150 meters with SA, and most units were constantly at the limits for altitude. For some reason, the 6000 was dead- on, possibly helped by a little more sensitive antenna or receiver. Dont forget though, that this unit also uses six batteries, has only eight hours of life, and is twice the price of the others; its really in a different class.
We also tested at night and found all units, especially the Magellan 6000, to be extremely readable. The Garmin 48 has the most readable screen of the sub-$500 units, followed by the Apelco, Garmin III, and Magellan ColorTrak respectively. (To Magellans credit, the switches are illuminated on both its models.)
The Apelco 11
This was the low-price leader with a very attractive, sleek case that, other than a two-year warranty, is its only claim to fame. It is also available in a Plus configuration that includes a power/data cable and very nice mounting bracket. The screen is very readable, but battery life was surprisingly low (about eight hours) for a simple unit with no special features. An economy mode is selectable which can double the battery life. In it, you can enter route information or waypoints, but the unit cannot receive satellites. The eight parallel channel receiver was more sluggish compared to the other units.
For whatever reason, this unit did not have the quick lock-on of the others. You also have to watch the satellite page for when the unit is useable for navigation by a 2D or 3D annotation at the bottom of the satellite screen. The other units automatically switch to a position page, eliminating the need to watch the unit or enter a keystroke to change to a navigation page. This unit has a customizable waypoint page in lieu of compass or highway mode as all the others have. In the waypoint page, you can select from a digital waypoint data display with steering pointer to a graphic waypoint data page or to a CDI page, with this last page being most useful for active navigation.
In field tests, we noted that the receiver would lock on to only three satellites for 2D navigation when in less than optimum conditions, such as under partial tree cover. By comparison, the other units locked on to four or more satellites under identical conditions. Horizontal accuracy was typically estimated as 440′ when all the others were at 75′ to 125′ under these conditions. Zoom range goes down to .05 mile (largest scale of the group) and up to 250 miles. There was no external antenna option.
Bottom line: Easiest of all units to slip in a pocket and cute as a button. An OK unit for the price-sensitive, but slower and not as feature-laden as the others in this group.
The Magellan ColorTrak
This was the only unit with a four-color screen (red, blue, green with a screen background of greenish white). Color can be helpful in designating waypoints, but this capability comes with a compromise as we explain below. The 25% larger display enables the use of larger characters in some screens and longer menus without having to scroll, but no big advantage over a clearer but smaller display such as on the Garmin GPS 48. The ColorTrak has no built-in navigation database, but does display moon and sun position on a navigation screen as well as good and best hunting/fishing times based on sunset/sunrise tables and moon phase. The value of this data may be of interest to select users.
The ColorTrak also has a temperature reading capability in either Fahrenheit or Centigrade. More importantly, the unit has nine navigation screens, of which five can be customized from a list of over a dozen choices. Because all but two of the screens can be deleted from the scan, this unit is very customizable. Our favorite is the compass screen that, in addition to making good use of the four-color display, also has a course-deviation indicator. Another useful screen is the four-parameter, customizable data screen with large, bold alphanumerics, visible from more than arms reach. We found the Magellan software to be a bit easier to use than the other brands without having to resort to the manual as often, even though the initialization process has more steps required than the Garmin 48.
On the downside, the color screen has a bluish-green cast that causes the contrast between the background and characters to be less sharp than, say, the Garmin 48 monochrome display. This somewhat offsets the value of the larger screen. We also found the optimal viewing angle to be noticeably narrower than a typical monochrome display. Lastly, the colors are rather muted and in many cases not especially beneficial. This is particularly true in lower light conditions.
Zoom range in plot mode is .1 to 400 miles. If you turn on the backlighting to improve visibility, battery life drops greatly. While the unit advertises 30-hour battery life, we did not experience such longevity based on the battery hours remaining indicator and our timing of actual use. We guess 25 hours would be a reasonable estimate. In an emergency, the unit can operate on only two cells.
One ergonomic problem is the push-buttons and rocker switch, which need more travel than we feel comfortable operating, and we found ourselves sometimes having to push a button two or three times to get a page change. With practice, we suspect a user would adapt to the more vigorous pressure requirement. We did not experience this key sluggishness with any of the other units except the Magellan 6000 (to a much lesser degree).
Bottom line: The ColorTrak has a nice software setup, but wed trade a bit of its generous battery life for a brighter screen. Screen customization and deletion capabilities are big pluses. The color screen has potential, but gives up advantages in loss of viewing angle and usability in dim light contions. Wed also rather see data memory used in more navigation-oriented uses than fishing timing charts that are available in other mediums.
The Garmin GPS 48
The evolutionary improvement to the GPS 12 and II Plus (not the 45XL as one might reasonably conclude), the 48 keeps the long battery life of 24 hours of the GPS II Plus model. (Theres a typographical error in the manual that says 12 hours). We found the unit particularly easy to initialize. Just turn it on and wait five minutes or so for it to find itself, or speed up the process to 45 seconds by indicating what country and state its in on a scrolling list. It was our consistent cold- and warm-start speed champ, taking only one key press and seconds to a position screen-a very big plus.
The GPS 48 has both a world city point (dots, not a map) and a nautical navaid database of foghorns, daybeacons, raycons, radio beacons, lit and unlit navaids, etc., indicated by 10 different symbols to show color, day/night, and the like. There are five primary screens from which users can page through and select submenus. You can elect to see either the compass page or the highway page with a course deviation indicator-your preference. The displayed page data is customizable from an options list, similar to the Magellan ColorTrak, with an adequate, if not as extensive, options list. Sixteen symbols are available to designate waypoints on the screen.
While the GPS 48 has a smaller screen than the ColorTrak, the entire unit is also significantly smaller and fits perfectly in the palm of the hand. The button-over-screen configuration allows for secure, one-handed operation, and the buttons respond just right to finger pressure. The screen is bright, generally easy to read, and has excellent contrast-noticeably more so than the ColorTrak. The zoom range is from .2 to 500 miles.
We still are not sure we like the rocker switches all these units use for waypoint data input. Recognizing lower-case letters, such as m and n when scrolling through the city points database, is the one situation when the screen resolution seems inadequate.
Like the ColorTrak, the GPS 48 has a detachable antenna, but it uses the very common BNC connector that allows for an easy, low-buck extension of the antenna with a generic RG-58 cable with BNC connectors. We made our own up for under $5, and found performance was good as long as we kept the cable under 6′ or so.
This allows you to easily use the GPS inside a cabin by sticking the antenna outside temporarily or in the boats window. If you want the official cable from Garmin, it will cost you about $100, but you get 30′ to play with and an amplified antenna (powered by the GPS) with outstanding performance. (Magellan uses an uncommon connector for its detachable antenna on the ColorTrak and 6000, so the cheap cable trick will not work with them, but an optional $100 antenna is available. Magellans reasoning for their connector is that it is a smaller diameter and passes through smaller holes and tight spots when running cable through the boat.)
The GPS 48 also has internal, selectable beeper alarms for such events as anchor drag, off course, etc.
Bottom line: We liked the GPS 48 unit a lot, particularly for sailors. The unit would benefit from lighted keys for night operations. The combination of a bright, mostly easy-to-read screen, nautical navaid and city database, great ergonomics, and the fastest starts, make this a tough unit to resist.
The database software can also be updated by returning it to Garmin. Its a winner.
The Garmin GPS III
The GPS III is the answer to the question wheres the map? that people expect to see in a GPS. This unit has a screen just a hair larger then the GPS 48, but it has a significantly better resolution with four levels of gray to make map reading possible. There are three versions of the G3, as it is affectionately referred to: One for the Americas, for which theres also a more costly pilots version and a third international version with more detailed maps of the world outside the Americas.
All versions have a distinctive triangular-shaped case that allows resting on a dashboard in a horizontal position. With the press of a button, the display can be rotated 90 to optimize the view you are interested in. The standard Americas version has a world map at high level, which can zoom down to 50 miles showing major cities. A much more detailed map of North and South America is also in the database. The U.S. portion of the map is the most accurate and inclusive, due to the much greater availability of electronic map data. The Canadian and Mexican maps are still quite extensive, the Central and South American segments less so.
Specifically, the U.S. map segment includes small lakes, major streams and rivers, principal urban areas, railroads, national, state, and some local level roads, as well as a more detailed coastline. Small cities and towns round out the database. Initialization and start times were very similar to the GPS 48. It also has the same easy BNC/detachable antenna setup. There is no provision for an audible alarm, although visual alarms are available.
Bottom line: This unit is a small wonder, with a tiny but still easy-to- read screen. Lighted keys make night operation easy. While not a boat-oriented unit, we couldn’t help but marvel at the built-in maps. A great choice for an extremely compact, all-around unit. For boat owners, the Garmin 48 is a better choice at $100 less.
The Magellan 6000
The 6000 two-channel model that we reviewed in our May 1 issue is now available in a 12-channel version. The big improvement of this unit is in initialization and start times over its two-channel predecessor. Other improvements include a velocity averaging and position window on the satellite status screen, larger map icons, increased world map detail, and higher resolution compass rotation on the pointer screen. Also new is a choice of five languages, selectable on power-up, as well as Swedish and Swiss grids. The 6000 represents the high end of the handheld market, costing more than twice the Garmin 48. For this premium, however; you get a huge, extremely sharp screen, with a built-in world map that can zoom down to a scale of 150 miles indicating major cities. The fun begins when you pop in a C-Map NT chart cartridge. In the prime coverage area of the cartridge (four would be needed to cover every part of Chesapeake Bay, for example), zooming can go down to .5 nautical miles which is extremely detailed. Depths, contours, buoys, wrecks, markers, etc. are visible. The 6000 can go down to a .1 nm zoom level, but the charting software ceases after .5 nm and you are in the plotter-only mode.
There is also another dimension to the C-Map NT coastal cartridge that improves its value outside the designated coverage area. As you zoom out to wider areas, you can still get C-MAP coverage-much more detailed than the built-in high-level map. For example, our lower Chesapeake cartridge has coverage up to New York Harbor at a zoom scale down to 15 miles, which is quite helpful, and as far west as the southern Great Lakes and north to Maine with a zoom range down to 50 miles. There is no inland data, i.e., Lake Champlain and the Finger lakes are visible, but not named. Nevertheless, the coastal value of the cartridge is much greater than the basic coverage zone. The Lower Chesapeake cartridge we used contains 25 charts ranging in scale from 1: 1,200,000 to1: 40,000, which is what gives it such versatility. A new, Wide C-MAP NT chart type (Cape Cod, MA to Block Island, RI, for example) contains 61 charts ranging in scale from 1: 1,200,000 to 1:2,500.
Initialization was not as stepless as the Garmin 48 (one keystroke was dedicated to language selection each time) but still easy and menu-driven. Warm and cold starts were quick and easy, but accuracy was not any better except for the previously noted altitude accuracy improvement. In spite of the expanded capability, this unit is easy to use because, in addition to the eight hardkeys and a rocker switch, there are four softkeys that change function to match the screen being displayed. This allows easier and faster operation than scrolling through menus and pages. There are four highly customizable navigation pages. While the unit is a handheld, it is also a handful and much larger than the other units-something has to hold that large, sharp screen. There is a provision for plugging in an external Magellan antenna.
Because the map scrolling function puts such a load on the processor, it blanked out as we scrolled off the edges of the display and the screen took several seconds to redraw at the new cursor location. The same delay was true of zooming in or out. The Garmin III did the same thing to a lesser degree. Theres just a lot of data to move around. This is not a problem for normal navigation where youre not zooming, panning and planning
Both Magellans also have beeper capability, and the added capacity to attach an external alarm via the data port and an optional cable (about $25).
Bottom line: A very powerful, compact, handheld GPS chartplotter with a great screen, day or night-but watch battery life. It uses the common C-Map NT cartridge. This unit is at the top of the current handheld GPS units, representing the confluence of current GPS technology, chart information, and ease of use.
Conclusion
GPS technology marches on and improved satellites are in the wings. We feel these 12 channel GPS units, combined with refined software, represent a big improvement over their channel-challenged predecessors in both acquisition speed and position accuracy. They just keep getting better and better.
If you can handle the extra size and cost, and want a portable chartplotter, the Magellan 6000 is tough to beat, though there are alternatives, which well continue to evaluate. If youre looking for an all-around, pocket-sized unit with land maps to boot, we recommend the Garmin GPS III.
Contacts- Apelco, Raytheon Marine, 676 Island Pond Rd., Manchester, NH 03109-5420; 603/647-7530. Garmin International, 1200 E. 151st St., Olathe, KS 66062; 913/397-8200. Magellan, 960 Overland Ct., San Dimas, CA 91773; 909/394-5000.
