Yukon Territory - North/Black/Liard River Canoe Trip, John's GPS

John, the techno-gadget freak of our group, had his new Garmin 12XL GPS unit (link to Garmin is below) along on our Yukon Canoe trips. GPS units are wonderful new toys, now quickly becoming more user friendly, more useful, and more affordable. GPS stands for Global Positioning System, and the receiver you buy is a very small hand held unit that uses satellite signals to compute its position with astonishing accuracy.

I do not consider a GPS indespensible for river work yet, though one can be helpful, and is certainly entertaining to have along. It might never be a necessary item as I have finally figured out that if I stay between the river banks I'll eventually get to where I want to go, well, as as long as I put in on the right river (there's a story there -- not mine, thank heavens). I do think a GPS could be very handy in a wilderness rescue situation where someone had to walk out for help. A GPS would definitely be helpful in a lake situation which requires a lot of intricate weaving among islands or picking the right one of many narrow bays.

The info that the GPS gives you is rather cryptic until you figure out how to interpret it, and easy after that. After learning it you might want to refamiliarize yourself with the system before heading out on a trip, especially if you don't work or play with the information reasonably often. GPS units do have to be used with a good map, and you have to know how to use that map in conjunction with the GPS receiver. The knowledge is worthless unless you can translate 132048 or even N61 22' 14.0" W130 37' 05.0" into a point on a map so that you can use the info supplied by the GPS. You do need to know where you are in relation to everything else, or it doesn't do you much good.

A couple weeks before the trip, John had used the Canadian topographical maps to figure out the coordinates of several places (called 'waypoints' in Garmin's version of "GPS-ese") along the rivers we were going to be traveling. He then used the buttons on his GPS to enter them into his unit's memory -- a tedious process, which can be made easier with the computer interface cable and software available for many GPS units (he now has that equipment). For our North/Black trip he figured at least one spot on each of the lakes as well as confluences with other rivers and creeks that should be rather obvious on the river portion of the run. On the Big Salmon he also added many of the campsites we used on our previous trip, which had been marked on the map during that 1989 run.

What you can do with these waypoints stored in the GPS memory is list them in a certain order and designate some or all of them as a 'route.' While on the trip you can turn the machine on and it will tell where you are on that route, and how far away from any of the waypoints you are by line of sight (not by river milage). Again, the info doesn't do you much good unless you can convert what the GPS is telling you into a point on a map. That is not hard, but doing it accurately takes a little practice.

Some of John's prepunches (before trip data entry) were off a little bit and John corrected them when we got to the actual place on the river or lake. To do that is simple. The machine knows where it is and can store that info in it's memory along with any info already there. He just had the unit record the position where he stood (push a button or two) and then delete the old coordinate. The actual process differs slightly between the various makes and models of GPS units.

John's machine gives elevation, but it seemed to always be off considerably, to the point to where I consider it useless. It would show our height above sea level as varying wildly -- as much as a 1000 feet off up or down. I am not bothering to list the elevation for any of the coordinate locations given because of this seemingly widely varying error. Knowing elevation accurately would be handy for figuring exact gradient in a river section, or for figuring the height of a hill or a waterfall. GPS manufacturers need to reprogram the receivers a bit before the elevation does us any good. Also the military has to turn off a built-in error factor in the transmitted signals. (It just wouldn't do for Saddam to hit us with missiles using a $100 guidance system he bought at K-mart!)

For ease on your own trip, I'm supplying the GPS coordinates in several different formats for you. The coordinate lists are at N/B/L waypoints and (future Big Salmon waypoints), all of which are listed in downstream order. As mentioned above, interfaces, cables, and software are available for many GPS units that allow you download this information from the Web page and transfer it to your GPS. Most cables and software programs will also allow you to transfer a list generated on your GPS to your computer. Some software packages allow you to make sophisticated maps with the information. For our use on the river, though, I don't see much use for the mapping stuff. At least until large scale topo maps of some kind are available on either CD-ROM, or over the internet, or when software is available to upload ones you've scanned yourself.

In a few more years, on-screen moving maps of the whole world will be available. These show an actual map of surface features on the screen and pinpoint where you are on the map. Such moving map GPS units are available, but expensive now, and detail is abyssmal (no topo features except roads and rivers). That will change. Map features (resolution) and accuracy will get better.

For those more interested in the possibilities of GPS, or a GPS web resource list, see the 'How To' Section of this Web site.

Link to Garmin: http://www.garmin.com/

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