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.