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!
