Navigation Software

I've been in Charleston long enough. After you soak up so much history, eat so many shrimp and grits meals, walk so many miles looking at truly magnificent homes, you're bound to take a day or three to explore some software. Ok, maybe not all of you.

So here's the thing: free navigation software. Now, NOAA has been supplying charts in digital formats for a few years now. Like books, there's nothing like a paper chart to keep track of where you are in the world (I can't translate lat and long numbers to a physical position in my head without a chart. I suspect most people can't).

Of course, chartplotters exist on many boats. I have two - a Raymarine C80 and a Raytheon Pathfinder as a backup. I'm very happy with both systems, but what about someone who doesn't have unlimited funds to acquire this stuff? What do they do? Well, here's the answer and it's way less expensive than you can imagine.

Maptech supplies charting software with its chart kits. It's copy protected, difficult to use, and requires, at this time, finding and installing an update to use Garmin hand-held GPSs. Because it's a 'lite' version of their charting software, there's a bunch it doesn't do. Moreover, it can only be used on one computer - if you need to move it to a different one, you have to convince Maptech that it's a legal move. Those 'features' are the kind that killed Lotus 123 and dBase as premier software packages in the '80s. Apparently big companies don't learn all that well.

That said, there are two programs that I know of that are free and use the free downloadable charts from NOAA.

Before I go there, though, there are two types of charts NOAA supplies called Raster Navigational Charts (RNC) and Electronic Navigational Charts (ENC). RNCs are a digital picture of the real paper charts. If you could print them out on a large size printer you would have essentially what you purchase in a store as paper charts - in fact, a company (Bellingham Chart Printers) exists that prints these files in grey scale for a fraction of the price of new colored charts. I know of world cruisers that have used them quite happily.

ENCs are data rich vector charts - they contain, essentially, a database of objects with attributes. If you query a mark, you'll receive the information about it such as name, color, purpose, height and other things. The charts themselves are visualized somewhat strangely to people used to using paper charts because they're line drawn. There's no shading. It's like looking at an architectural drawing, except with buoys.

Most chart plotters actually use both chart sets - the visualization is with the raster chart so it looks familiar, but when you click on something for information, it querys the underlying vector chart based on your cursor position and you get the presentation of the information.

Don't worry if this is getting too technical - if you're familiar with the transparencies of the human body in an encyclopedia (most have them) then you can picture how this works. If not, just take my word for it.

Now for the programs. The two I'll discuss are SeaClear II and OpenCPN. Although both are capable chart plotters and navigation aids, OpenCPN offers the ability to control the autopilot and set and save routes to follow. Both integrate easily with GPS units, with SeaClear II able to connect to Garmin units using the USB without modification. The OpenCPN uses NMEA 0183 exclusively.

Sea Clear II uses the RNCs and is very easy to use - it is not designed to be a full fledged navigation system, in my opinion. But it is very easy to use and very useful as a chart plotter. It allows you to make routes and save waypoints. I've used it for couple of years and it's great for deciding overall trip strategy. I like it alot.

I've recently been turned on to OpenCPN. I'm a big fan of open source software and I use Open Office instead of paying Microsoft huge sums of cash for a questionably useful product. But I digress. OpenCPN was written specifically to do all the things a chart plotter does - run autopilots, set and follow routes, provide information about navigational items and much more. As you move from place to place the program automatically loads the chart for that area at the closest scale it can find for where you currently on. Sometimes, that takes a few seconds, but I suspect that has more to do with my computer than anything else.

OpenCPN uses both RNCs and ENCs as I've explained above. There's a huge implication to this fact - first, all the charts that NOAA provides are free to download, and second, if you have a PC with a decent monitor and three USB or serial ports and a GPS unit you can have a full fledged navigation system/chart plotter. It will run any NMEA 0183 autopilot (like, for instance, Raymarine). It will use any NMEA GPS antenna (like, for instance Raymarine or Garmin). And it will run on Windows and Linux (and maybe Mac but I won't vouch for that). It accepts AIS input and displays it. It is very powerful.

So, if you wanted a system you could purchase a decent laptop for $500 or so, load it with Ubuntu (free linux), install the OpenCPN, connect your autopilot, your GPS antenna ($250), your AIS receiver (optional, but fun $500) and you'd have the equivalent of a $3000-$6000 system. Moreover, with a little ingenuity, you could add a display at your helm with a touch screen. To be perfectly honest, I'm tempted to try this myself...

Anyway, there you have it - free navigation software. If you've got the time and a PC, I'd sure enough have a look at both. The charts are free from NOAA - RNCs and ENCs. I find downloading them by Coast Guard Zone the easiest. Unzip to a directory you'll remember and point the program at it - then go to town (sea)!

That's it for now. I'm leaving Charleston to spend Christmas with friends in Brunswick GA.

See you on the water!