About 8 years ago I went fishing with a buddy in Shenandoah National Park, on a stream that didn’t have a trail along its banks for several miles. It was April, the fishing was superb, and I was having a lovely time until I realized the shadows were getting kind of long.
Even though I had a paper topo map with me, I had no idea how far I was from the “take out” – a trail that crossed the stream somewhere between 2 and 4 miles upstream from where we were fishing. We began a forced bushwhack up the streambed, and didn’t get back to our car until about half an hour after sunset. This was too close for comfort. As soon as I got home I ordered a handheld GPS from Amazon.
It took me a few years, but now I use the GPS a fair amount, especially when I need to bushwhack. But even if you’re hiking on trails, it’s helpful to keep you oriented in places you’ve never been before, and to estimate accurately how far you still have to go. It’s also a great way to record where you’ve been, and to make personal maps to share with friends or for future reference.
A comprehensive guide to using a GPS is well beyond the scope of this website, but I thought it would be useful to share a few tips. Send me an email if you think more information would be helpful and I’ll consider expanding this information.
What Kind of GPS should I Use?
If you don’t use a GPS very often, you may want to consider using the GPS in your smartphone. But be careful! Three issues you need to worry about.
- The GPS chip in your phone will continue to work even if your phone loses a signal, but the background map may not. If you’re lucky (and especially if you’ve been looking at the area you’re heading for) the maps may be in your phone’s cache. But you’ll want to keep the phone on as long as possible and as close to your destination as possible while you still have a signal.
- Phones aren’t waterproof. Make sure you get yourself a waterproof case, or a zip lock freezer bag, and make sure it’s completely sealed before heading outdoors. An easy way to “brick” your phone is to get it wet.
- Make sure your batteries are fully charged. The GPS and mapping software will burn through your battery pretty quickly. This is fine if you’re just looking at the GPS to find the trailhead; problematic if you’re depending on it for navigation after you arrive. Make sure you have printed map backup, and consider getting an external battery pack to extend battery life.
If you expect to use a GPS often, I would recommend a waterproof, mapping GPS designed for outdoor use. Garmin has a good selection and the broadest support in the industry (both in the commercial and the open-source world). So I’d recommend buying the Garmin model that fits your budget. A color screen is important for map legibility. In theory you could probably use a battery powered auto GPS (loaded with topo maps), but if you do so, the same comments about a waterproof bag and extra batteries are in order here.
Geez, those Topo Maps are Expensive! Anything I can do about it?
Garmin sells US 24K topo maps in regional DVDs for $129 each. The entire US requires 6 regions, and will therefore cost you over $800 with sales tax to get the entire country. It’s a lot of money and completely unnecessary. Yes, the Garmin maps are nice, but there’s a robust open-source community creating reasonable mapping products that are completely legal, fully compatible with your Garmin GPS, and free. You can find several sources by searching on the web (try a search for “open source Garmin-compatible Topo maps”), but I’ve had good success with a website called GPSFileDepot.com. They provide 24K topo maps state by state that install easily using the same Garmin software (e.g. Basecamp) that will install Garmin products on your GPS.
The reality is that ALL GPS maps work from the same USGS databases that are available online for free. The open source map you download won’t be as pretty or slick as the Garmin one, but it’s almost certainly as accurate.
How Can I get WildTroutStreams Data into my GPS?
There are two basic approaches to this, which translate into infinite variations: 1) to export Custom Maps, which are essentially images that you geo-register prior to importing into your GPS unit, or 2) to export KML data as objects that your Garmin GPS understands, e.g. tracks and waypoints.
Approach 1: Export Custom Maps
This is a relatively new feature on the latest generation Garmin GPS units. Essentially you capture an image, say a jpeg, of a map (or part of a map) you want to display on your GPS. You then import it as an “image overlay” into Google Earth, and geo-register it by aligning the map image with features on Google Earth. Then you then save the geo-registered image from Google Earth into the CustomMaps directory of the memory card on your GPS unit. If you did all of this correctly, it will then display your custom map properly aligned with your basemap. This process is documented in detail on the Garmin website.
A few comments:
- This approach works only with the latest generation Garmin units. If you have an older unit (like I do) you’re sort of SOL. There is some 3rd party software that hacked together a different solution, but the market is shrinking as these units go out of service, and the software is barely supported.
- The image overlay tool in Google Earth is pretty cool, but not particularly easy to use. We’ve used it a lot to create KMLs for this site, and it can be extremely frustrating to align features properly. In particular, many 3rd party maps use different projections that may not be compatible with Google Earth’s, which means that features will NEVER line up perfectly.
- While this is great if you have a map someone else created that you want to import, it doesn’t make all that much sense for a lot of the data on this website, which is essentially vector data. If you have a decent topo map in your GPS unit, why go to all of the trouble to convert it to a custom map? There’s an easier way.
Approach 2: Export Tracks and Waypoints
Generally speaking, the data in this website comes in a KML, and almost of of it is pretty straight-forward paths (for streams) or markers (for places). A path is just a series of straight lines connecting geo-registered points. A marker is just a geo-located icon image. In GPS lingo, a path is called a “track” and a marker is called a “waypoint”.
The image on the right is a screen capture from my own, “old school” Garmin unit, a 60CSx. The basemap is an open-source topo map of NJ I downloaded from GPSFileDepot for free.
The black dotted lines are segments of a park boundary I found in Google Maps, and traced using the drawing tools you can find there. I then exported the boundary line as a KML. The red and magenta lines represent existing woods roads in the park. They were originally tracks I captured on my GPS and imported into Google Earth (even the free version will talk to your Garmin unit and import information like that). I then used the drawing tools in GE to “clean them up” and, again, saved them as a KML. I’ve put them in the GPS to help me navigate back to them when I’m bushwhacking. For fishing, you could as easily export a stream as a track, or mark places you want to explore.
How did I get them into my GPS? Simple, I used an open source software package called GPSBabel. It will read in a KML and convert it to a Garmin-standard GPX file. This is then loaded them into Basecamp and sent out to my unit. It took me about 10 minutes to figure it out the first time, and now takes about 2 minutes.
Your unit may have limits on track storage you’ll need to take into account. For example, my 60CSx is limited to storing 20 tracks, even though I have 4GB of flash memory installed. Turns out this memory is only useful for maps, and doesn’t increase the capacity to store tracks.
How Can I get my GPS Data into my own Trout Workstation?
One of the easiest ways to do this is using Google Earth. As already mentioned, even the “free” version of Google Earth will load tracks and waypoints from your Garmin GPS automatically. Once in Google Earth, you can drag everything into a folder, and save the folder as a KMZ or KML file using the “Save Place As…” dialog from the file menu.
You can, of course, simply save the raw information as a KML. However, it’s usually better to smooth out the tracks captured by the GPS: I usually draw over them using the path tool in GE, to get a nice, even line.