Features February 2006 Issue

Electronic Charts

Navionics’ Platinum and Gold charts excel over C-Map and Garmin

Relying on a powerboat to cover more ground quickly for our testing, we compared four cartography cards. The Garmin BlueChart, loaded in the Garmin 3010C (top left); the Navionics Platinum, in a Raymarine E120 (top center); the C-Map NT+ Max, in a Standard Horizon CP-1000C (top right); and Navionics Gold, in the Northstar 6000i (flush mounted in console, lower right).

In addition to providing finely detailed charts for display on screen, today’s cards supply a plethora of additional information that mariners find extremely useful. A few years ago, we might have told buyers to look first at what plotter they liked and then live with the cards it came with. After all, they were all pretty much the same. Not today. The latest releases from

C-Map and Navionics have so much additional information that it takes a chartplotter with a very powerful processor and a high-resolution screen to fully exploit all of the cards’ capabilities. Today, picking your chart card is just as important as picking the plotter that will display it.

What We Tested
Vector chart card makers C-Map, Navionics, and Garmin, were all contacted for this review and asked to supply their latest and greatest chart card along with a large-screen plotter capable of showing all the features and capabilities the card has to offer. C-Map elected to send an NT+ Max card installed in a Standard Horizon CP-1000C. Garmin choose to send a BlueChart 7.5 card and a Garmin 3010C chartplotter to display it.

Navionics’ most recent release is its much-heralded Platinum chart card. As of this writing, the only machine capable of fully utilizing this card is a Raymarine E-series plotter. We reviewed the card on an E120 display. Because the market for the Navionics Platinum card is currently limited to only one plotter, we elected to evaluate the Navionics Gold, as well. This card was assessed on the 10-inch Northstar 6000i we currently have installed on our Contender open fisherman for long-term review. All charts covered a similar area of the southeastern US and Bahamas.

How We Tested
We temporarily mounted the plotters and their respective GPS antennas on the Contender to review features and accuracy. Testing took place off Islamorada in the Florida Keys. As far as was practical, we minimized any variability in position data by mounting all the GPS antenna modules within two feet of each other on our T-top. Card features were given ratings based on the readability, usefulness, and accuracy of the data being displayed. For instance, we picked a lighthouse or beacon in our local area and checked how each chart card displayed the name, color, shape, light sequence, and light sectors. We also confirmed that each unit was giving us the correct position data for each navaid we checked. We combined all the ratings and data collected by checking numerous lights, buoys, and day beacons into an overall “navigation aids” rating.

Other overall scores for the items listed in the table on the next page were obtained the same way. For the depth data rating we combined marks obtained from reviewing each chart’s depth contouring, depth shading, and some spot soundings.

For the shoreline accuracy rating, we tracked the display for several miles of coastal shoreline, around a couple of offshore islands, and through a meandering salt creek.

For the cruising crowd, we came up with a harbor-information rating by looking at marina information, diagrams, photos, and zoomed-in cartography.

Fishermen will notice the wreck rating. PS visited five wrecks charted (four wrecks were on all the cards and a fifth was displayed only on the Navionics cards) in the local area to determine if any of them could be located strictly with the chart card data. Any additional wreck data provided was also factored into this rating. Traditionally, electronic chart makers have obtained wreck databases from government sources like the Automated Wreck and Obstruction Information System. In the past, many wrecks from this source have been difficult to locate due to position errors in the system. This seems to still be the case, as not one of our plotters led us to any of the five wrecks we sought.

C-Map Max
Certainly, any of the chart cards we tested will get you where you want to go safely. However, we did not find the subtle chart details on the C-Map NT+ Max to be on par with either the BlueChart or Navionics cartography. For example, in one case, the C-Map chart boundary did not line up with the boundary of an adjacent chart, and in another case, a highway going over a bridge did not line up with the chart display. Such coverage gaps, or inconsistencies, are more than just annoying, they can lead to errors in navigation if you’re not careful.

Depth contouring and spot sounding on the C-Map Max were accurate in most areas. We did, however, note a lack of contour detail in some small channels and waterways.

C-Map claims the Max chip has 32 levels of color available for depth contouring, but in our area, which included depths ranging from 0 to more than 200 feet, the chart only used one shade of blue to show the water areas.

During our navigation aid review, the C-Map Max failed to display the names of certain buoys when there were more than one or two located in fairly close proximity to each other. In some cases, only the buoy color was displayed.

One notable feature available on the Max card is dynamic display of the buoy light color and sequence on the plotter chart page. So the flashing nav aids you see on your display match what would appear in the real world. To get other buoy information, the user must move the cursor over the buoy or beacon. Once you do this, the buoy name — and, if applicable, light sequence, light sectors, and usable distance — appears on screen in text form. We’d prefer that the names be displayed at all times on the chart page.

When we checked the accuracy of government-placed marker positions shown on the chart page, they all proved to be exactly correct.

The display of tide and current data with the Max chip is well thought out and easy to decipher. Once selected via a menu option, the tide display shows times of high and low tides in a chart and in text. It’s easy to select which tide station or day you want.

In many charted areas, usually around bridges and entrances to harbors, color-coded arrows indicate current direction and speed. Placing the cursor over the arrow generates a pop-up window that gives current direction in degrees and knots. This handy type of current display is not available on any other chart card except the Navionics Platinum.

While navigating through a winding mangrove-lined creek, we noted the Standard Horizon CP-1000C and its C-Map card placed us up on the shore several times at distances up to ¼ mile — even as our boat traveled right down the middle of the fairway. We can’t be sure whether the machine or the cartography are at fault, but none of the other unit/chart combos showed this degree of inaccuracy at this location. At highly zoomed settings, the C-Map chart lines representing shorelines, island outlines, and channel banks appeared somewhat pixelated and blocky.

The C-Map Max card has a small library of 640 x 480 pixel photographs containing panoramic shots taken from a low flying aircraft. Most of these shots look over channels and harbors. A camera icon on the chart page identifies an area that has a photograph in the library. We did not find any photos in the library covering our local creek and harbor, but we did view some of other areas and found them useful in gaining an overall perspective of the area.

Another feature of the Max chip is a library of high-resolution harbor drawings that resemble the other cartography on the card. We found a small harbor in our area with a chart and accessed it simply by zooming in on that area. We’d opt for a good bird’s eye view photograph of a harbor over the harbor drawings.

Perspective view is available on the C-Map Max card and can be displayed on the CP-1000C by turning it on in the main menu. It is valuable for gaining an awareness of the area from a differing viewpoint. But due to range restrictions, its usefulness as a navigation tool in our area was limited.

We couldn’t locate any of the four wrecks using this cartography and machine.

Bottom Line: The C-Map Max boasts some nifty features, but cartography inconsistencies and its limited photo library hurt its overall score. C-Map’s Ken Cirillo addresses some of our findings on page 16, “C-Map Responds.”

Garmin BlueChart
The BlueChart is the most expensive chip in our group, but it also has the largest coverage area. We think its basic cartography is better than the C-Map’s but not as good as the Navionics. We found most chart details to be accurately drawn, though when highly zoomed some shorelines and islands took on a rather blocky appearance.

Depth contouring and spot sounding on the Garmin BlueChart were detailed and accurate in the areas we covered. The only glitch was an erroneous spot sounding in Tavernier Creek. Garmin makes use of different colors to emphasize contour detail in varying water depths. Depth contour coloration cannot be altered independently. You can only change contour colors when you select a different color palette for the display unit.

BlueChart displays buoy, beacon, and lighthouse names clearly on the chart page, even in channels where numerous navigation aids occupy limited water space. We found this advantageous when transiting channels that require precise awareness of your position. At a glance, the boat operator could match the day beacon number on the chart to the actual beacon. On large lights, where the beam is sectored to warn mariners of hazardous areas, the BlueChart only sometimes displayed this information on the chart page. When it was not displayed, moving the cursor over the buoy or beacon yielded a listing of the light color, sequence, sectors, and usable distance. Accuracy of buoy, day beacon, and lighthouse positions displayed on the chart page was good.

As we idled through our test creek, the combination of the Garmin 3010C and the BlueChart 7.5 edition chart card sometimes showed us tracking the edge of the channel when we were actually in the middle, but it never showed us in the bushes. Even though the deviations were minor, we can’t be sure whether the machine or the cartography is at fault here. Any time you are navigating in close quarters with a digital chart, you can’t be guaranteed precision.

Harbor cartographic information is limited in the BlueChart. No additional photography or diagrams are provided to enhance your view of most confined harbor areas.

The BlueChart shows wrecks just as you’d see them on a paper chart. There’s no additional information. We tried to find four wrecks but found none.

Bottom Line: A basic card with good overall cartography, but it’s too expensive for what you get, in our view.

Navionics Gold
The Navionics cartography provided the best all-around detail and the most variety of information.

Shorelines, islands, and channel banks in our test area offered more accurate representations of the real world on the Gold card than the C-Map or BlueChart cards.

Depth contouring and spot soundings on the Navionics card were accurate in all the areas. Depth contour detail was good in deepwater areas and clearly superior to the C-Map cartography in several nearby areas we checked. These areas have usable small boat channels running through flats. The Navionics and Garmin cartography showed the channels and the C-Map did not. Spot soundings and depth contour colorization is user-adjustable in the Northstar 6000i display when fitted with the Navionics Gold card.

As we reviewed navigation aids, we noted that the Navionics Gold card displays buoy, beacon, and lighthouse names, shapes, and colors on the chart page. Additional navigation aid information is obtained by placing the cursor over the marker for a text pop-up of buoy name, and if applicable, light characteristic, sector, color, period, and the effective range. All the marker locations we checked in the Navionics Gold card were accurate.

The tide information page on our Gold card system is a full-screen display that you select with a single button push. The page presents a large graph of tide data, which we found very easy to read. Date, station name, and next high and low tide are also shown in text format. Station and day changes are made with one or two button pushes. As we wound our way through creeks and along shorelines, we found the Navionics cartography to be both accurate and more closely representative of the real world than either of the other two cartography programs. Generally, it showed us in the correct position and had drawings of shoreline and islands that matched reality well.

One problem we noted was the Northstar’s inability to zoom in as far as the other machines. Also, on the tightest zoom level, the depiction demonstrated a significant loss of resolution, giving it a rather grainy appearance. We tried the Gold card in the Raymarine E120 and had no problem zooming the Gold card down to the Raymarine’s minimum 1/32 of a mile range.

Harbor cartographic information is limited in the Navionics Gold card. No additional photography or high-resolution marina diagrams are provided to enhance your view of most confined harbor areas.

The Gold card showed a few more local wrecks than either the C-Map or Garmin, but we still could not locate any of the five we checked.

Bottom Line: Excellent all-around cartography at a reasonable price.

Navionics Platinum
Navionics Platinum cartography appeared to be identical to the Gold card cartography. Shorelines, islands, and channel banks in our test area offered very accurate representations of the real world. No glitches were noted in any of the Navionics cartography.

Depth contouring and spot soundings on the Platinum card were accurate in all the areas we covered. As with the Gold card, depth contour details were good in deepwater areas and superior to the C-Map cartography in several local areas we surveyed. Spot soundings and depth-contour colorization were user-adjustable in the Raymarine E120 display that was fitted with the Navionics Platinum card.

The display of navigation aids in the Platinum card is identical to the Gold card, with buoy, beacon, and lighthouse names, shapes, and colors on the chart page. Additional navigation aid information is obtained by placing the cursor over the marker: An object table opens onscreen and displays in a very user-friendly format everything you’d want to know about that particular navigation aid, including name, light color, light sequence, light sectors, and usable distance. All the position checks were accurate.

Both tide and current information are available on the Platinum card. Icons for each are displayed on the chart page. Moving the cursor over any icon and clicking OK brings up a table with the appropriate information. Though the display for each has all the needed information, we thought the tables were a bit overloaded with information and might be somewhat difficult to use for some. We like the Gold card’s clean, straightforward tide display as it appeared on the Northstar better. C-Map’s use of colored arrows and timely heading and speed data, which are displayed in a simple format, really make using their current information easier.

The Navionics Platinum cartography matched the Gold card in accuracy and real-world representation. Underway, it generally showed us in the correct position and had shoreline and island drawings that matched reality. We noted no problems with zooming on the Raymarine E120; it went down to a very tight 1/32 of a mile range.

Photographs — and lots of them — are what set the Platinum card apart from the Gold card. Navionics has placed a huge library of aerial and satellite photos on the Platinum chip. The panoramic and harbor photos are viewed at nearly full screen when selected. They provide a bird’s eye view of many harbors and coastlines. We found numerous panoramic photos in our local waters even though they are located far from a major metropolitan area. The satellite photos are used to overlay the land areas only, or both the land and water areas as the user selects. Opacity is totally controllable too, so you can adjust how much you want the photos to blend into the cartography. We found it worked best when the satellite photos were placed over land only. They added detail there without adversely affecting depth contour lines, spot soundings, or the location of navigational aids.

The Navionics Platinum 3-D view is similar to the perspective mode in the C-Map Max but far more powerful and adjustable. Just as the name implies, it provides a three-dimensional view of the selected area. As with the C-Map perspective mode, the Navionics 3-D view is a great tool for enhancing your situational awareness, but it’s not the most effective means of navigating. To make it more useful, it can be displayed in a split-screen mode with a 2-D top-down chart. One of the downsides we noticed immediately when using the 3-D view was how hard it was working the Raymarine E120 processor. Screen refresh rates were slow.

The wreck database in the Platinum card is larger and more detailed than any of the other cards. It lists exact GPS coordinates and sometimes other information about each wreck. But just because the coordinates are listed doesn’t mean the wreck is located exactly at that spot. We were unable to find any of the five local wrecks we attempted to locate using any of the cards’ data.

Bottom Line: It’s pricey, but the Navionics Platinum takes top honors for its excellent cartography and ton of value-added features.

Finding highly detailed glitch-free cartography should be your number one priority when choosing a card for your plotter. Both the Garmin BlueChart 7.5 and Navionics Gold cards make the grade here. We’d gladly use either to traverse our local waters and take an occasional out-of-area trip. Though the Garmin has a slightly larger coverage, it is three times the price of the Gold card. Given that we’d go Gold card.

If you’re shopping for a card and plotter at the same time, you’re in a position to look beyond the basics and go for the latest and greatest. The Navionics Platinum takes the prize here. We think the extensive photo library alone is worth the extra bucks for a cruiser. Just the peace of mind one will get from seeing an aerial shot of an unfamiliar harbor or a particularly treacherous section of coastline is worth the price of admission—to say nothing of the variable photo overlay, 3-D view, and current predictions. The Navionics Platinum card only works in Raymarine E-Series plotters now, but within a year or so we’d expect to see several other machines with Platinum capability.


Also With This Article
"PS Value Guide: Vector Cartography"
"C-MAP Responds"

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