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.
