Navigating the Great Loop
Janet Crane and Jeremy Bell
Electronic Navigation - Chartplotter versus PC
We have a Raymarine chart plotter which came with out boat that we use for most of our navigation. It has worked great on the eastern coast of the US and through most of Canada. There were areas of Canada as well as down the rivers where either there were no map chips available, or the detail was not very good. On the plus side, the screen is very easy to read, there is a direct link to our GPS so we can see were the boat is on the chart at all times, and since it only runs navigation software it has been very reliable (knock wood). The downside is the cost - you have to buy the proprietary chart 'chips'. The chips run $200 each and we ended up having to get about 10 chips to do the trip. So - unless you already have a dedicated chart plotter, or only need charts for a very limited area, I wouldn't necessarily recommend it.
The alternative to a dedicated chart plotter is to use a PC with
charting software. The plus side is that most folks these days already have a PC
or laptop on board. The downside is that the screens on most laptops are
not really bright enough to navigate by, especially in bright sunlight. We built a hood (out of some
black cardboard) to shade ours, but it still isn't that great. One of our friends ended up getting an external 17" monitor that they hooked to their laptop. The one they got is very bright and the size works well when looking at charts underway. The other negative of using a PC for
navigation is that it can crash. Dedicated chart plotters are a lot less complex and have only one function, so they do tend to be a lot more reliable.
Electronic Charts -Vector versus Raster
The first thing to know about PC-based electronic charts is that there are 2 basic types: Vector and Raster.
Raster Navigation Charts (RNC) are basically 'scanned' paper charts. They were the first electronic charts as they were the easiest to produce. As with any digital image, they tend to get a bit fuzzy if you zoom in too much on one area of the chart. They are updated whenever the underlying paper chart is updated.
Vector charts (called Electronic Navigation Charts, ENC or IENC) are composed of electronic co-ordinates and data, used by the chart program to dynamically 'build' the chart display as required. Because they consist of data, it is possible to update individual items and areas, as well as add additional features like tide/current calculations. Unlike raster charts, the picture tends to stay clear and provides more detail as you zoom into a particular area. There are many differing formats of vector charts (eg Garmin, Nobeltec), and they seem to be incompatible! This is just like the early days of computers - and just as frustrating. However, there is a strong push to standardize charts to something called the S-57 format.
All chart plotters are vector-based. Most PC programs will read either vector or raster-based charts.
You can download (for free) charts for many of the inland rivers from the Army Corps of Engineers web sites as well as coastal charts from
NOAA. They are in the S-57 format, they should work with most of the PC based chart plotters. These were the sites we used to download the charts. Many of the rivers are managed by different Army Corps districts, so some offer electronic downloads and some don't. I've included websites we found for the various rivers below.
NOAA Introduction to Electronic Charting:
http://chartmaker.ncd.noaa.gov/staff/faq.htm#copyright
Mississippi River
http://www.mvd.usace.army.mil/gis/navbook/main.html
Ohio River
http://www.uscg.mil/d8/mso/louisville/rivercharts.htm
Cumberland River (US Army Corps)
http://www.lrn.usace.army.mil/opn/CumbRiver/cumbmap.htm
Tennessee River
http://www.orn.usace.army.mil/opn/TNRiver/
NOAA
Raster: http://nauticalcharts.noaa.gov/mcd/Raster/download.htm
Vector: http://chartmaker.ncd.noaa.gov/mcd/ENC/index.htm
Maptech Chart Kits
http://www.freeboatingcharts.com/
PC Programs
The Government agencies (NOAA and Army Corps) make the charting data available,
but do not supply the program to display it. There are some free or demo
programs available, but these are often restricted in some way (either a
time-limit, or no GPS interface). We use a PC program called Fugawi, and there are several others available. Some of our friends have Coastal Explorer, which looks to be a little easier to
use - take a look at a few and see which one seems the best for you. When
selecting a PC based program, be sure that it can read many chart formats - both
raster and vector charts in the free S-57 format, as well as their own
proprietary charts.
CARIS free charting program:
http://www.caris.com/products/software.cfm/prodID/33
Paper Charts
We carry paper charts of all of the areas we're going through in addition to electronic
charts for several reasons. Firstly, electronic charts can crash, especially if
you are running them on a PC. Secondly, paper is the way to go when doing long range planning.
Thirdly, we've found it invaluable on the rivers when talking to the tow boat captains. They will often call and give their location
as 'XYZ bar' or 'Joes Cement Plant' on the river. It's much easier to flip through a paper chart and find the location than scrolling up and down on an electronic chart.
In addition it's always best to leave your electronic chart zoomed in on your current position. We once saw a boat take the wrong turn on one of the rivers. When I called him to tell him, he said that he had scrolled off his current area to try to find something else on the
charts. Paper charts can be ordered in advance, but are usually available at
marinas and marine stores in the areas covered by the chart.
Paper charts for the Canadian waterways were usually available at the Parks Canada office at the start and end of each canal.
Cruising Guides
In terms of cruising guides, we highly recommend all of the Skipper Bob books. They have
great information on anchorages and marinas along the way. The intracoastal waterway book also lists comparative dockage and fuel rates. Granted the rates will be from the previous year, but they provide a good guideline as to which marinas are a bit more expensive than others.
Skipper Bob has a deal on his website on the complete set needed for the Great Circle trip (look on the Ordering page). We ended up buying them one at a time and wish we'd bitten the bullet and bought them all before we left. They are not always that easy to find along the way.
http://skipperbob.home.att.net/index.htm
Sad note: Skipper Bob passed away this past year, but his wife, Elaine, plans to maintain the guides and continue to publish them. He will be sorely missed by the boating community.
We also carry the Waterway Guides (Southern, Mid-Atlantic and Great Lakes). We found these very useful in terms of providing detailed information about marinas as well as charts showing marina locations. The guides also provide excellent write-ups for the various towns and cities you will travel through. They do not, however, have a lot in the way of information about anchorages (we found the Skipper Bob books to be an excellent resource in that regard).
For the Tennessee River and the Tenn-Tom, we found Fred Meyers books (Cruising the Tennessee River and Tenn-Tom Nitty Gritty) to be excellent resources.
http://www.cruisingguide.com/cp/Scripts/prodView.asp?idproduct=25
Our favorite cruising guide for the North Channel in Canada was called 'Well Favored Passage' by Pixie Haughwout and Ralph Folsom. This is an excellent guide to this beautiful part of the world.
http://www.seafevergear.com/north.html
AGLCA
If you are thinking of doing the Great Loop trip sometime in the future, I would join the America's Great Loop Cruising Association (AGLCA). The dues are $33 a year, and you receive a bi-monthly newsletter containing lots of valuable information about the loop. When you leave to go on the Great Loop trip, be sure to sign up as a member of the current AGLCA Google group. This is an 'invitation only' group that allows folks who are currently doing the loop to share information. You need to be a member of the AGLCA to join. Send an email to Steve Kromer when you leave, he will add you to the list.