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Choosing a GPS for hiking

Updated: Sep 20, 2023

My personal thoughts on choosing a GPS for hiking - your preferences or needs may differ. 

Only Garmin units will load my Garmin-format Big Sur Trailmap (as well as many other free maps), so I will only discuss them.  The Garmin eTrex 10 cannot load additional maps, which is greatly limiting (and it has a black+white screen) so I will not consider it.  Unfortunately, I've never used a "wrist watch" type of GPS, ala the Fenix or Foretrex, so cannot review them here - they will not display my Garmin-format Trailmap so you would have to load trail GPS tracks instead (if you have used such, I'd like to hear of your experience)

Touchscreen vs buttons:  while a touchscreen works well indoors, outdoors it can be touched by something other than your finger, especially if off-trail (depending greatly on how it is attached/carried) - with unwanted results.  So I've sometimes had to put my Oregon into "Lock Screen" mode for traveling, then "Unlock" to use it, then back into "Lock" mode, etc - which is a pain in the neck.  So I now only use GPSes with buttons out in the field, i.e. a GPSMAP 64 or a eTrex 20/30, and will only consider those below. 

Pre-loaded terrain maps:  only for the technology-challenged user, since free maps are readily available and easily installed. 

Size:  the GPSMAP 64 has a bigger screen and often easier to read than the eTrex 20/30 but is also more bulky - personally I find the eTrex screen is often "good enough".  Very large screens, such as the Montana, I find too cumbersome for hiking. 

Reception:  the GPSMAP 64 has a quad antenna and more sensitive chip so will give a more accurate location and lose lock less frequently that an 20/30.  But I've found the eTrex to be generally "good enough", even in deep canyons. 

Altimeter/compass:  the GPSMAP 64s and eTrex 30 have a barometric altimeter and electronic compass, the GPSMAP 64 and eTrex 20 have neither - one pays about $40 to have those sensors.  I find the barometric altimeter useful, since I like to see small elevation changes as I hike.  But note that elevation information is available on all GPSes - it is obtained from GPS signal itself but vertical positioning has more error than the horizontal positioning so must be averaged, hence accurate small elevation changes requires a barometric altimeter (which is itself calibrated by using the averaged GPS signal).  The compass has a much larger error than a magnetic compass so is not as useful as it might be - but is better than nothing. 

Ease of use:  Although requiring a bit of learning, I find the buttons-only GPSMAP 64 much easier to use than buttons+joystick on the eTrex 20/30, since the latter requires moving a cursor selection bar both horizontally and vertically with the joystick, so I must look at the screen to see what I am doing.  The GPSMAP 64 has more buttons, so their functionality can be more specific - and they are more conveniently located so I can easily use the GPS with just one hand, holding it in my palm while pushing buttons with my thumb.  So after memorizing the button locations, I can do many operations such as changing displays without having to stop hiking - I do the button push sequence needed, without looking at the GPS, then glance at the screen to get the information I need while continuing to hike!  I love that! 

Battery life:  Identical batteries are used for the GPSMAP and eTrex models, but the latter gives significantly greater battery life due (partly) to its smaller screen. 

Cost:  as of January 2019, discount house [e.g. The GPS Store]  prices of the eTrex 20, eTrex 30, GPSMAP 64, and GPSMAP 64s are $150, $190, $210, and $250. 

My personal choices:  I like having altimeter and compass information so all my GPSes are "sensor" models.  For "big" hikes, e.g. off-trail hikes or when I expect to have to use the GPS a lot, my choice is the GPSMAP 64s - I'm willing to put up with the increased bulk since it has a better antenna (so better accuracy) and a larger screen.  And I can operate it using one hand while continuing to hike!   But I use the smaller eTrex 30 when on many "normal" hikes where I already know the route and don't expect to use the GPS much, or when a hike is very long so battery life might be an issue.  [And on my "mapping" hikes I take at least 2 GPSes, both as backup and because their tracks can be averaged afterward to give better mapping accuracy.]

GPS Usage

Some thoughts on GPS usage:

Read the on-line manual:  Ok, that's asking too much - the GPS has lots of features, many of which you will never use.  But do quickly skim the on-line manual, which is more detailed than the quick reference provided with the GPS, to see what is possible and what features you might want to use sometime.  Do read about those features you definitely will be using - that will save much trail-and-error frustration.  Of course you should read about the controls, the buttons and the joystick to learn what they do.  Link:  Garmin manuals.

Setup:  Again, there are lots of possibilities under the Setup screen, many of which you will never use.  Again its a good idea to quickly look through all the possibilities to see what you might want to change - something you later dislike about the GPS operation might in fact be changed through a Setup option.  Some Setup possibilities you should definitely be aware of are:
Satellite System:  controls GLONASS setting (see below)
Battery Type:  needed for correct Battery Level display
• sets battery saving options
• many user-preference options available - but note that these settings can also be changed by using the "Menu" button while displaying a map
Select Map allows display of loaded Garmin-format Big Sur Trailmap
• many user-preference options available, such as choice of color of current track to display on map
Auto Archive sets how often the "current" track will be "archived" - I recommend the "Daily" setting, so on your next hike the track from your previous hike will be stored (this will increase your startup time slightly)

Batteries:  Since I use my GPS on every hike, I use the highest capacity "pre-charged" Ni-MH rechargeable batteries available, 2550 mAh AA Eneloop Pros.  I now habitually put them in the charger the night before a hike when assembling other gear the night before a hike.  For rechargeables, make sure you use a "smart" charger which automatically drops the current after a full charge is reached - otherwise you will damage the battery and reduce its capacity.  But note that even the highest capacity rechargeables will not last as long as non-rechargeable Lithium batteries.  Always use the same two batteries paired together - that will keep them matched in capacity, since battery life is determined by the weakest battery. 

Battery life:  Of course battery life depends upon the amount of usage beyond simply recording a track, e.g. panning the map bank and forth, finding along-trail distances, etc.  And it especially depends upon the amount of "backlighting", used when the screen is not in direct sunlight.  [GPS screens are designed to be used outdoors, so unlike smartphones their screens work best in direct sunlight.]  Note there are several options to control the amount of backlighting used - e.g. you can have the backlighting turn on automatically when a key is pressed and then turn off 15 seconds after the last key press.  Note: use the GPS's "Setup" to set the type of battery used, since the battery level display relies upon that information. 

GLONASS:  Many Garmin GPSes are now capable of using the Russian GLONASS positioning satellites in addition to the US GPS satellites.  Using both will increase accuracy - theoretically, GLONASS should be particularly helpful in the narrow canyons often found in Big Sur.  But it also drains the battery much faster.  I find the accuracy added by those satellites is relatively small, around 10%, and so not worth the battery drain unless accuracy is very important. 

USB connection:  Note that connecting the GPS to a PC via a USB cable allows direct access to your "archived" tracks as GPX files under the GPS's "Garmin"->"GPX"->"Archive" directory. 

BaseCamp software:  The free Garmin "BaseCamp" software allows interaction with a USB connected GPS, notably downloading tracks and waypoints to be displayed on a background map.   BaseCamp has many capabilities, for example allowing you to archive tracks and waypoints and then display all of your hikes on a single map.  But unfortunately that also makes BaseCamp complex to use.  Tutorials and videos can be found on-line. 

Jack Glendening
Trailmap Forum