View Full Version : GPS Coordinate Preference

09-10-2010, 09:36 AM
I plan to add GPS coordinates to my maps. What GPS coordinates do you prefer on fishing/hiking maps? Using Hazel Creek Cascades area as an example, here are the options:

Decimal Degrees (WGS84)
35.541667 -83.583333
Degrees, Minutes & Seconds
N35 32 30 W83 35 00
N 35 32.500 W 83 35.000
17N 265805 3936185

USGS & Trails Illustrated use Degrees, Minutes & Seconds in 2 min 30 sec intervals in the margins plus Full UTM Grid lines. Sportman's Connection, which specializes in lake maps, uses only Degrees, Minutes & Seconds with grid lines in 30 sec intervals


09-10-2010, 12:19 PM
I prefer UTM.

09-10-2010, 03:58 PM
...work with my Garmin :)


Jim Casada
09-10-2010, 06:33 PM
Fred--I don't know a GPS from an iPod (or is it iPad) or Kindle, but common sense tells me that the way for you to go would be the way the majority of GPS units display the information. If you'd like I can ask my brother. He's a whiz on this stuff and uses a GPS until to plot all kinds of stuff while he is in the backcountry, especially off trail.
Jim Casada
www.jimcasadaoutdoors.com (http://www.jimcasadaoutdoors.com)

09-10-2010, 08:07 PM
Jim, yes please, ask Don for advice. Other than the modest one I have in my van... and when on a trail..., on my person :smile:, I have yet to acquire a unit of the type Don has. Someday soon maybe.

I do indeed wish to design to how the majority of GPS units display the information (my reasoning for asking), but also to be able to add to all the maps with a minimum amount of time involved. With the latter point in mind, my preference at this time is full UTM Grid plus Degrees, Minutes & Seconds in the margins, but perhaps with a tighter 30 second interval.

Mike, can you tell me the model number of your Garmin?

John, thanks for casting your vote.

I still want to hear from other GPS users.


09-10-2010, 08:38 PM
I have a couple of Garmins, one is the older ETrex Vista, a B/W Handheld that's about 4 or 5 years old and likely outdated. The other is a Nuvi 1690 (I think) that I keep in my car. Not sure on the model number cause I have had to return a few due to firmware glitches and tended to trade up each time.


09-10-2010, 09:46 PM
I've never seen a GPS that didn't have all the coordinates listed, plus some.
I prefer the UTM, because I think it's easier to "eyeball" your location with the UTM grid coordinates on 7.5 minute maps. As we all know, using a GPS AND a MAP TOGETHER is the BEST thing to do. Technology can let you down at the most inopportune moments.

09-11-2010, 09:47 AM
I'm sold. It will be Full UTM Grid and, in the margins, lat/long notations in 1 min intervals. I anticipate the Eagle Creek map being complete in a few days.

Thanks for the input!

Here's what a member of a mapping forum (cartotalk.com) said in reply to my post:

"I would use NAD 83 UTM 17North for the GSMNP area. Lat/Long is great for navigating a boat across the ocean but kinda cumbersome to navigate a person from one hole to another hole on the same creek."

Sounds as though kru has been there, done that.


09-14-2010, 06:56 PM
that's my choice

09-15-2010, 03:31 PM
Thanks, Sam, and to the others who have replied here and to Don Casada for his very helpful e-mail. The figure below illustrates what I plan to go with on future maps starting with Eagle Creek. Over time the coordinates will be added to new editions of previously published detailed maps.

10/8 Update: Eagle Creek (http://www.smokystreams.com/maps/ltreec01.htm) is finished. Working on adding to Hazel Creek at present.

The blue values and grid lines represent the Universal Transverse Mercator (UTM) grid coordinate system. The black values are longitude/latitude coordinates stated in degrees-minutes-seconds with the tick marks and alternating B&W bars at 30 second intervals. I considered using decimal degrees instead for longitude/latitude, but the values take up more margin space than is available.

For those interested in more info on the topic:
Geographic coordinate system (http://en.wikipedia.org/wiki/Geographic_coordinate_system) Wikipedia.org
GPS Coordinate Converter (http://boulter.com/gps/) (one of many available)
(I cannot vouch for the credentials of the authors or the accuracy of content of these sites).

Thanks again.

10-20-2010, 08:58 AM
Eagle Creek / Lower Hazel Creek GPS-compatible map set is complete. LRO has them.


10-23-2010, 07:27 PM
Nice Work!

10-29-2010, 11:24 AM
Thanks, John.


11-01-2010, 09:47 AM
I am late, but glad you ended up going with the UTM coordinates. From my experience in the Marine Corps, the UTM is just the easiest to use.



11-01-2010, 09:20 PM
Good deal, John. Thanks.

11-04-2010, 09:57 AM
I have found this new Delorme PN-60W pretty exciting. Now, I just need to get someone to buy my Garmin Oregon 400i.