EDITOR'S NOTE: The End Of The Series

If one single aspect of e-charting most concerns boaters, it's the exchange of data. Can you create waypoints and routes on a laptop and transfer them to a chartplotter? Can you display boat instrument data on your PC? Can you use the same cartography on your PC and your chartplotter?

In theory, the answer to all these questions is "yes." But not all applications can do all things, and even if they do, they vary considerably in their ease of implementation. In this part of the series summary, we examine the 14 software packages we reviewed and their ability to network and exchange data, support common ship's instruments, and display the bevy of electronic chart formats now available to boaters.

As we have mentioned, the real added value of a PC in your navigational toolkit is the creation and sharing of assets such as waypoints and routes. You keyboard and mouse ashore, saving customized collections of pre-planned routes, anchorages, marina locations, fishing holes or any other digital annotations to your charts. But for many, the laptop is not a fixture on the boat. For them, all that planning will have no value if the data cannot be uploaded to a chartplotter.

THE WEAK LINK

Unfortunately, the exchange of data across marine electronics, PCs, and applications remains the weak link in the e-charting chain. Some vendors place a high priority on the sharing and exchange of data. They freely publish and share their data format protocols, encouraging other vendors to develop integrated products. Others have circled the wagons, protecting their proprietary formats in an attempt to force you to stay within their family of products. These vendors keep their information secret, so companies that want to share data must "reverse-engineer" the design to integrate products.

If you intend to use your PC to prepare navigation data for a chartplotter, then data exchange is an important factor in your choice of an e-charting application. However, if you envision your PC as primarily a way to preview charts, or you intend to use it for dedicated tasks such as fuel calculation, or you only have a few local waypoints and routes that you've long ago entered into your chartplotter, then data exchange is certainly less important.

Data can be exchanged in two ways. You can physically transfer the data via a storage device. For example, data can be moved to a chartplotter using a Secure Digital (SD), Compact Flash (CF), or MultiMedia (MM) card. Data can be moved PC-to-PC via CD or USB drive. Alternately, data exchange can occur over a network, such as a cable between your chartplotter and your PC, an ethernet cable for PC-to-PC local area networks (LANs), or even an emailed file to another boater.

However, the practical aspects of data exchange are a bit stickier. For example, let's say you want to transfer your PC waypoints and routes to your chartplotter, which takes Compact Flash cards. In order to save the data from your PC onto a CF card, you must have a card reader, a small external device that connects to a PC's USB port. Some e-charting packages, such as Fugawi Marine ENC or Raytech RNS, bundle their software with these devices.

The second potential obstacle is the format of the data. Simply saving a data file of waypoints and routes onto a CF card has little value if the file cannot be read by your chartplotter. Although all navigation software is designed with some form of "Input/Output" (I/O) capability, they vary in the data formats they support. In order for data to be exchanged, it must be stored in a way so other devices or applications can read it.

DATA EXCHANGE

The most constrained form of data exchange works only across that company's software and instruments. For example, Nobeltec VNS and Admiral use their "Open Navigation Format" (ONF), which only allows for the exchange of information between Nobeltec devices. In our assessment, communicating solely within a single vendor is not data exchange, it is data interchange. Similarly, Raytech RNS has extremely convenient data transfer to its own devices (via an ethernet cable), but can accomplish only rudimentary data exchange with devices made by others, and even that is with the aid of a helper application such as GPSBabel. Although these data conversion utilities are inexpensive, they effectively require you to hand-map your data from one format to another, not a task for the data-squeamish.

A better approach, although not the best, is to allow data to be saved and transferred in generic computer text formats such as comma-separated value (CSV) files. CSV files are universal and unconstrained, because they simply store the data as plain text separated by commas (or tabs in the case of tab-delimited data).

However, this flexibility often creates trouble when transferring waypoint and route data. Comma- or tab-delimited data transfers typically require a bit of handwork for a successful import or export. For example, should the "N" in the latitude be placed before or after the numerals? Should there be a space between characters? Since comma- and tab-delimited files do not dictate the specific data format – only that each data field is separated by a comma or a tab – we've often experienced errors in data transfers. The most severe occurs when waypoints are omitted or their positions are shifted (sometimes slightly, sometimes grossly). This was the case in our DigiBOAT test. Intracoastal Waterway waypoints appeared about five miles offshore!

The smoothest transfer of data uses GPS Exchange Format (GPX), a standardized XML format for the exchange of GPS data. Because the GPX specification dictates the precise format of the data, it guarantees a direct and accurate transfer. With GPX, we easily and accurately transfer literally thousands of waypoints between e-charting applications and between computers (even with different operating systems such as Macs and PCs). MacENC, Fugawi Marine ENC, Coastal Explorer, The Capn (routes only), Chart Navigator Pro and MaxSea all support GPX.

Finally, a fun data exchange extra is appearing recently for those applications that integrate with Google Earth. If waypoints or chart annotations can be saved as KML files, they can be imported and displayed as a layer on a Google Earth satellite image. MacENC, Fugawi Marine ENC, and Coastal Explorer support export to Google Earth.

The applications also differ in the extent of menu help they provide to assist with data transfer. Integrated GPS transfer means the application provides menu choices that send the data automatically via cable connection. For example, a series of menu and submenu choices may be Waypoints>Transfer to>Garmin. NavimaQ, MacENC, Fugawi Marine ENC, Coastal Explorer, Nobeltec VNS, Chart Navigator Pro, Nobeltec Admiral, and MaxSea all provide some form of integrated GPS transfer feature.

GPX FORMAT

Be warned: the details and logistics of import/export are typically not as straightforward as the marketing teams (or our Feature Comparison Table) suggest. Many applications can only export certain navigation objects, such as waypoints, but not others, such as chart marks or routes. Some applications are robust at exporting data but are limited on importing. Some will import and export to certain devices made by certain vendors (such as Garmin or Humminbird) but, even then, not to all models. In short, the import/export details of any e-charting application are much more complicated than our Feature Comparison Table implies. With so many devices, formats, and frankly, programming quirks, it is impossible to detail all the subtleties of data transfer. If integrated data exchange to your chartplotter is an important feature for you when it comes to buying navigation software, we again suggest downloading an application's demoware and rigorously exercising this function.

Overall, any application that supports GPX has a greater chance of successfully importing and exporting a wide variety of navigational objects to a wide variety of other applications or devices. Also, when any package is used exclusively intra-company, such as Raytech RNS with its intended Raymarine instruments or Furuno MaxSea with its current NavNet line of hardware, it should be smoother sailing.

The catch is that most boaters do – or eventually will – care about data exchange. Unfortunately, it's hard to predict what form of data exchange you may want in the future. What if you eventually switch e-charting applications and don't want to lose all your waypoints and routes? What if you switch from a PC to a Mac? What if you upgrade to a new chartplotter? What if you meet other boaters who have navigational assets you'd like to swap? To prepare for the greatest flexibility, GPX is the safest long-term choice.

INSTRUMENTS

Most boats include networked marine electronics, allowing data from a GPS sensor to appear on a chartplotter, or the VHF radio to transmit position in an emergency, or the autopilot to steer routes created on the chartplotter.

These marine devices typically talk through NMEA data, transmitted over a network of cables. If you bring aboard a PC equipped with an e-charting application, you now also have the option of connecting some of these marine instruments to your PC. In this case, your PC can display data collected from your instruments, such as GPS position, depth, wind speed and direction, AIS ship traffic or even radar scans. Or, your PC can transmit data to your marine devices, such as route information to an autopilot.

All the applications listed in our Feature Comparison Table are NMEA 0183 compliant, which means they have the potential to understand data from other marine devices. Many are struggling toward compliance with NMEA 2000, a revised standard that promises to make instrument connections plug-and-play. In the interim, NMEA 0183 remains the only show in town, despite the well-known joke that its connectivity is "plug-and-pray."

The potential to understand a data string is not the same as the ability to display the data. As a simple example, in order to display anenometer data, the e-charting application must be programmed with an interface (such as a window or data field) to display wind speed and direction. So any application, although it can read NMEA data, may or may not support the display of that particular information or all its underlying data.

Before you scan the Feature Comparison Table searching for an e-charting application that supports the most instruments, ask yourself what instrument data you need to see on a laptop while underway. Your answer will depend on your helm situation and the type of boating you do.

EVALUATING CONNECTIVITY

Because laptops are not marinized, and even the brightest screens are difficult to see in sunlight, a laptop will need to be kept down below on boats with open or exposed cockpits, such as sailboats or small powerboats. Conversely, trawlers or cabin cruisers with enclosed helm stations and flat navigation stations will easily be able to view the laptop screen while underway. Cruising catamarans like ours fall in the middle: a laptop needs to be out of the cockpit but is likely to be visible just inside the bridge deck.

Whether your laptop is at the helm or down below influences what instrument data will make sense to display. A window of AIS data is of little value if it appears on a laptop buried in the salon. It only makes sense to dig deep into the instrument display choices if your laptop is used at the helm.

Second, whether your laptop is at the helm or down below, not all boaters need all instrument data. For example, do you really need water temperature displayed on your PC? You do if you are a Gulf Stream racer or an offshore fisherman. But for most boaters, this one bit of data probably isn't worth the cabling hassle. Ask yourself what instrument data you really need to network to your PC. Keep in mind that it's okay if your laptop is an island of information. It still serves an important purpose in creating waypoints, planning routes and obtaining supplemental information such as weather – even if it is stowed and augmented by marine instrument displays and devices such as chartplotters while underway.

Despite this seemingly glib comment, instrument connectivity is absolutely a major component of an e-charting package's features. Even the lowest-priced choices support an impressive number of instruments. For example, DigiBOAT's Software-On-Board, at only $53, can connect to every instrument with the exception of a video camera. Even SeaClear II, the freeware choice, displays everything except water temperature and video. Instrument support is a clear example of the "arms race for the most features" that we mentioned earlier in this summary.

Most boaters care about instrument support for three devices, in priority order: GPS, autopilot and AIS. Instrument data such as wind, water temperature, radar, electronic compass or video become either more specialized or more complicated to implement. The Feature Comparison Table summarizes which instruments are supported by each package. Note that some cases are not as straightforward as suggested by a simple yes or no. For example, Nobeltec Admiral is listed as supporting radar scan displays. It does – but only after the purchase of an expensive proprietary analog-to-digital translation device ("black box") or, more likely, a new radar, options that will run several thousand dollars.

GPS, AUTOPILOT, AIS

A GPS sensor is the most important instrument to connect to the PC, showing the boat's position on a chart. Without a GPS, even the most sophisticated e-charting application becomes a crippled viewer or planner. All boaters should exploit the power of an e-charting application by connecting a GPS. Fortunately, this does not mean difficult or inconvenient cabling from your PC to your vessel's existing sensor. A much easier solution is to purchase a redundant USB GPS sensor for less than $100, such as the GlobalSat BU-353 or Garmin GPS 18. These hockey-puck-sized units simply plug into your PC through its USB port.

Autopilot and AIS connectivity are next in line when it comes to popularity. All the applications we reviewed support autopilots, allowing you to auto-steer routes created and stored in your PC. With the exception of Raytech RNS, all the applications also support AIS collision avoidance. Although this relatively-new feature is particularly popular right now, it is not necessary for all boaters. It's most relevant if you cruise in areas with heavy shipping traffic, such as Puget Sound or the Chesapeake Bay.

The remaining instruments are primarily for boaters with particular needs. For example, wind display is needed if you intend to use sailing route optimization. Water temperature is useful for fishermen. However, for most boaters, making use of your standard marine instrument displays is sufficient.

Many e-charting applications also connect to radar instruments. However, as we pointed out in yesterday's article, receiving data from a radar can mean many things: ranging from basic collision avoidance data to full color radar scans overlaid on a chart image. Most e-charting applications connect to a radar, but check the Advanced Feature rows for Radar (ARPA/MARPA) and Radar (display overlay) in the Feature Comparison Table for details on what you can expect from this instrument connectivity.

Nearly all of the applications are able to connect to a heading sensor or electronic compass. This feature is primarily supplemental, providing more granular data than GPS position. Although, note that heading sensor data is required for radar overlay on a chart image.

Finally, a handful of applications tout video camera support. BoatCruiser, The Capn, Nobeltec VNS and Admiral, and Raytech RNS can display a small video window on your PC screen while you perform your regular navigational work. It's a flashy feature, but realize that video is a notorious hog of computer memory, bandwidth and chart display area. However, some boaters may have a need to monitor a child's stateroom, an engine room, or fighting chair on the aft deck.

CARTOGRAPHY

An e-charting program is only as good as its cartography. But the choices for digital chart formats are overwhelming. How do you choose an e-charting package based on its cartography?

First of all, don't choose an e-charting application based on the cartography you currently use for your chartplotter. The two use charts in different ways and the chances of sharing charts in a way that saves money are thin.

Instead, when weighing the cartography choices, think about where you expect to cruise long term. It's widely acknowledged that chart quality varies by region. For example, Nobeltec Passport Deluxe charts now include the accurate Explorer Charts for the Bahamas, a region notorious for its bad cartography. However, according to many forums, Nobeltec Passport charts have poor coverage for the Sea of Cortez in Mexico, a popular cruising destination for West Coast boaters. Research the differences in chart quality for your particular cruising geography by talking to other boaters and searching the forums.

If you plan to cruise outside the U.S., then you should consider e-charting applications that can read a variety of international formats. Although international vector charts are standardized, only the U.S. government distributes its cartography in an unencrypted S-57 format. Other countries take their vector charts and encrypt them, necessitating an unlock utility, or use an evolving standard called S-63. A surprising number of e-charting applications do not read international S-57 or S-63 charts (see Feature Comparison Table).

International raster charts also come in country-specific formats. For example, British Admiralty charts (ARCS) do a good job covering British territories, including the British Caribbean, British Isles, and Mediterranean. Of the applications we reviewed, only MaxSea reads ARCS. Canadian Hydrographic Service charts cover Canadian waters. Seafarer charts specialize in Australia and New Zealand. If you intend to travel to remote international areas without adequate digital coverage, you may want an e-charting application that lets you scan and geo-reference paper charts. Only SeaClear II and Fugawi Marine ENC currently have this feature.

In addition, five vendors support proprietary vector charts on chip and/or CD format. Software-On-Board, BoatCruiser, and MaxSea use C-Map cartography. Fugawi Marine ENC and Raytech RNS work with Navionics charts. Although private vendor charts are more expensive, they are generally of high quality and include rich supplemental data, since each company's focus is chart production.

FREE U.S. CHARTS

Glamour destinations aside, the majority of U.S. boaters will confine their cruising to U.S. waters, which means they should care about support for free RNCs, ENCs, and IENCs for U.S. coastal and inland waters.

We feel strongly that any e-charting application used by U.S. boaters should read free U.S. charts. Our government is unique in providing free, frequently-updated digital cartography. Yet a surprising number of e-charting applications do not support free U.S. vector files (ENCs or IENCs). For example, SeaClear II, NavimaQ, TIKI Navigator, The Capn, Nobeltec VNS, Raytech RNS, Nobeltec Admiral and MaxSea only read the raster format files (RNCs). Software-On-Board supports neither RNCs nor ENCs.

Some e-charting vendors take the approach that the more formats supported the better. For example, Fugawi Marine ENC, BoatCruiser and Coastal Explorer support an impressive assortment of chart formats. Some of the applications even let you view multiple chart formats simultaneously. For example, with MacENC and The Capn you can view a traditional-looking raster chart while harnessing the intelligence of an underlying vector chart. The Capn goes one step further and can blend the transparency level of the raster chart over the vector chart.

Other vendors intentionally restrict their chart compatibility. Some do so for navigational reasons, such as DigiBOAT's view that vector charts are superior to raster charts. DigiBOAT also stays away from scanned charts, believing that scanning old paper charts is a bad navigational practice. Other vendors restrict chart support for commercial reasons, presumably because they are also in the vector chart-selling business, as are Nobeltec or MaxSea.

Finally, realize that your choice of navigation software has an economic impact on your annual investment in cartography. Digital charts have very different "nautical mile per dollar" value. Regardless of which charts you use, you should update them annually. NOAA charts are continually updated at no cost. NavSim BoatCruiser is unique in providing an auto-update feature (for a one-time fee) that compares and updates your free NOAA charts. Several certified chart distributors sell NOAA compilations for less than $50. In contrast, some chart vendors provide new cartography through paid updates, annual membership options, or by requiring full-priced purchase by chart region.

With the computing power on today's laptops, digital cartography is no longer restricted to nautical charts. Many e-charting applications also allow you to display satellite and aerial images, topographic maps, and 3D bathymetric views of the seafloor. However, this supplemental data is usually not included with the e-charting application. You must purchase cartography that includes these extras, such as Passport Deluxe, C-Map MAX Pro, or MaxSea Bathy Charts.

Satellite images are most useful for boaters who frequent areas with poor charting and/or shifting channels. Many applications display these satellite views. Additionally, some programs support aerial "Nav Photos." Note that while these applications accurately geo-reference and display the satellite imagery, few programs can properly indicate where Maptech Nav Photos are available. Thus, without Coastal Explorer or Chart Navigator Pro, a Maptech Nav Photo is a proverbial needle in your file folder haystack.

For the five applications that support C-Map or Navionics cards, aerial photos are provided as part of the supplemental data. About half the applications support topographic maps, which we find less useful. Traditional charts show elevation so topographic maps don't contribute much to on-the-water navigation. Finally, and most specialized, nearly all the higher-end applications allow for the display of bathymetric data.

CONCLUSIONS

Although data exchange may be the weak link in the e-charting chain, you can minimize problems by identifying capabilities that are important to you and then choosing navigation software that best support those capabilities.

When it comes time to import or export data, nothing compares to the GPX standard. Because of their full support of GPX, MacENC, Fugawi Marine ENC, Coastal Explorer, Chart Navigator Pro, and MaxSea score high in data exchange.

Instrument connectivity is strong and relatively uniform across today's e-charting choices. All of the applications, with the surprising exception of Raytech RNS, support the "big three": GPS, autopilot, and AIS. In fact all but NavimaQ and Fugawi Marine ENC support most instruments.

Chart support, on the other hand, differs considerably across the products. Some programs, such as Software-On-Board, go with a single chart source (C-Map). This single-sourcing, particularly to the exclusion of free U.S. charts, makes it impossible to recommend to U.S. boaters. In contrast, some applications support multiple formats but are unique in supporting a particular format, such as MaxSea and its unique support for British Admiralty ARCS.

Overall, two companies stand out in the cartography category: Fugawi Marine ENC and NavSim BoatCruiser. Not only do they support many formats, they support both free U.S. cartography and at least one of the high-quality proprietary chart sources. Fugawi supports Navionics. BoatCruiser supports C-Map. Furthermore, BoatCruiser is the only e-charting application today with an auto-chart update feature.

TOMORROW: Our favorite picks among the 15 products we reviewed.

Capt. Mark Doyle and Capt. Diana Doyle are authors of the Managing the Waterway cruising guide series, and their work has appeared in numerous publications. They also produce CDs and DVDs of NOAA and USACE charts.