A friend once asked me to recommend the least expensive Chart Plotter I knew about. My answer was, you need to build it yourself if it is going to be inexpensive! Recently, two MSA members have come up with related questions. This is my opinion about how to put together a system that can get you, with minimal expense, into the wonderful world of electronic navigation.
Any Electronic Navigational System comprises of at least four fundamental parts:
- A Global Positioning System (GPS) receiver.
- Some sort of Map, or Ocean Chart, that shows things or places based on Earth Coordinates.
- Software that receives the GPS signals and combines them, on a screen, with the Map or Chart.
- A computer that runs the software.
In order to put together my first chart plotter design, I’ll deal with this list in reverse order.
The computer that runs the software
Some chart plotters are constructed using a dedicated single board computer (SBC) that runs proprietary software. These chart plotters are available from companies like Raymarine, Garmin, Standard Horizon, etc. For my first design we are going to use a general purpose small computer, preferably a laptop computer. For now, I will not add the cost of the laptop. In another installment I will talk about different ways an old laptop, or a fairly inexpensive SBC, can be used to run the chart plotter software.
System Component One: Laptop computer running Windows XP (price: whatever you can buy, borrow, or steal)
The Software that runs on the computer
Software for electronic navigation is available from the companies that make dedicated chart plotters, as well as from companies that write the software only. Raymarine is a company that makes both. The software only product from Raymarine is the Raymarine Navigation System (RayTech RNS 6.0 http://www.raymarine.com/default.aspx?site=1&SECtion=2&page=1384). This is a very sophisticated system that provides functions useful up to the level of professional mariners. RayTech RNS 6.0 is expensive for the purpose of this article. Nevertheless, I’ll talk more about what it provides that sets it apart from other entries presented here.
rom the software only camp, we get entries like The CAPn http://www.maptech.com/water/thecapn/index.cfm. The CAPn is the grand daddy of navigational software. The CAPn is distributed by Maptech, which also writes Chart Navigator and Chart Navigator Pro http://www.maptech.com/water/chartNavigator/index.cfm. MaxSea is another old timer in the navigational software arena (http://www.maxsea.com). Jeppesen marine produces Nobeltec Visual Navigation Suite (VNS v9.3) http://www.nobeltec.com/products/prod_suite.asp.All the about programs, except for Chart Navigator, can set your wallet $400 to $600 lighter.
A more recent entry in the software category is Fugawi http://www.fugawi.com. Fugawi’s Global Navigator is reasonably priced at around $135. This software has been my favorite to play with, when I’m not playing with a networked version of RayTech RNS. More about a boat network in the future. Global Navigation Software also has a package in the price range of Fugawi’s Global Navigator; it is the NavPak Electronic Charting Systems or NavPak ECS http://www.globenav.com .
My friend always says, “The best price is free.” In this category the winner is SeaClear II http://www.sping.com/seaclear. I have to say, SeaClear is in the category by itself. It is the only chart plotter software I know is free of charge. If you use SeaClear, please give credit to the author, Sping AB; a lot of work has gone into writing this software.Although SeaClear lacks many desirable features, this is the package we will use in the first design.
System Component Two: SeaClear II Navigation Software (price: free)
The Maps and Charts for the Software that runs on the Computer
I wanted to include maps to leave open the possibility of using our chart plotter on the road. For now let’s say that maps are very close to one kind of navigation chart that we’ll discuss later. For a comparison of maps and charts see http://chartmaker.ncd.noaa.gov/staff/map-cht.htm.Nautical charts for use with software are classified in two categories: Raster and Vector based.
Raster charts are produced by scanning the official government paper charts. The scanned images are saved in different formats; some of the formats have become standards. The software uses the raster chart format to read the scanned images and then display them on a screen. Vector based charts are produced by specifying nautical characteristics using a numerical format. There are no images in a vector chart, just numbers following a standard specification.
Vector charts are newer than raster charts and they offer many more features. The specifications for the International Hydrographic Organization S-57 standard can be downloaded from http://www.iho.shom.fr/PUBLICATIONS/download.htm. Vector charts are commonly known today as Electronic Navigation Charts (ENC).In the past, the government assigned private companies to scan the official paper charts. These companies are licensed to sell the scanned charts to the consumers; same system as what the government has for paper charts. NOAA had an exclusive agreement with the BSB Chart Company and the first raster charts got to be known as BSB Charts. For years, Maptech was the best known company distributing raster charts, their implementation added compression the BSB format. Maptech packages the raster charts into CDs that correspond to the regions assigned to the paper charts. The price for these charts is around $100 per region.With the explosion of the World Wide Web as an electronic data distribution mechanism, the National Ocean Service (NOS), part of the National Oceanic and Atmospheric Agency (NOAA), distributes electronic charts from the Office of Coast Survey. First, raster charts were the only type available; today, both raster and vector charts are available. The raster charts are named NOAA RNC (NOAA’s Raster Navigational Chart). The vector charts are named NOAA ENC (NOAA’s Electronic Navigational Chart). The choice of the navigation software impinges on the charts we can use.
For my software choice, SeaClear, I must use raster charts. NOAA RNC can be downloaded from http://chartmaker.ncd.noaa.gov/mcd/Raster/download.htm.
System Component Three: NOAA Raster Navigational Charts (price: free)
The GPS that signals the Software
If you have a portable GPS device like an old Garmin 45, you’re almost set. If you have a data cable to your portable GPS, then you are ready to play. You can get instructions for a DIY Garmin data cable at this site http://www.syz.com/gps.My choice for a GPS for the chart plotter is a Bluetooth GSP Receiver. These units connect wireless to any computer that has a Bluetooth transceiver.
If you computer does not have Bluetooth, you can get a GPS receiver that connects to a serial port or a USB port. Better yet, my choice for computers without Bluetooth, but with a USB port available, is to get a Bluetooth transceiver for the USB port. These Bluetooth devices can cost you from $15-$30 online. My choice is a GPS that has WAAS and a minimum of 12 channels. Most of the units that you find today have 20 channels. The number of channels is one of the factors that affect the speed the units get a fix; the more channels, the faster to get a fix if the satellite signals are strong enough.Here is a site that sells GPS receivers online: http://www.buygpsnow.com. Here’s a link to the Bluetooth GPS receivers http://www.buygpsnow.com/bluetooth-gps_9.aspx. Last, this is a link to a Bluetooth transceiver for USB port: http://www.buygpsnow.com/globalsat-bta-806-bluetooth-dongle-520.aspx.
Select a receiver that can accept an external antenna, can be recharged from a 12v source, WAAS, and 12 channels or better.So, go ahead, equip your computer with a GPS receiver, the chart plotter software, and some charts for your cruising area. Next time I’ll talk about how I use the chart plotter.
System Component Four: GPS Receiver (price: $40 t0 $80)