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Garmin GPSMAP 66st Review ─ Best Handheld GPS

Want your hiking stints to be stray-free in the middle of the trip? This Garmin GPSMAP 66st Review will surely provide a clear fresh breather by offering in-depth insight into how the brand’s product is easy on the wallet and offers convenience at its best.

The Garmin GPSMAP 66st is a high-quality topographic map guide. Featuring top quality and eco-friendly materials, Garmin has surpassed its predecessors in terms of quality. It offers a wide array of features otherwise found in overly priced other GPS models. Designed to ensure life safety while on an outdoor adventure, it allows the user to send and receive text (SMS) and email messages to anyone in the World with a phone that can get ordinary texts and emails, making it highly reliable. 

All GPSMAP 66 models now include an ANT+, Bluetooth, Wi-Fi, as well as USB services. The brand suggests that these portable gadgets using Birds Eye satellite imagery subscription, direct-to-device downloads, TOPO Maps, and Multiple Global Navigation Satellite Systems (GNSS) can be your reliable partner in the long run, which makes them worthy of your every dime and consideration were you on a hunt for the best high-quality GPSMAP gadgets available.

Garmin GPSMAP 66st

Connected and In-Built Features

  • Live geocache data for mobile syncing and updates.
  • Smart Phone notifications. 
  • Connect IQ.
  • Active Weather feature provides up-to-date forecasts with animated weather radar.
  • Track downloads.
  • EPO download for a faster satellite reception.
  • Live/Group-Track.
  • Birds Eye download.
  • Activity uploads to Garmin Connect and Garmin Explore.
  • Software updates.

What to Expect from Garmin GPSMAP 66st?

The Garmin GPSMAP 66st essentially is a souped-up version of other models offered in the already high-end GPSMAP series. The 66st employs the use of a high-powered, quad helix antenna as well as offering a staggering 16 GB memory along with micro-SD 64GB card space now available, and it roughly quadruples the storage up to 80GB, which is way more than we think we could ever use in the lifetime of a unit, without ever deleting anything.

Operating on principles of receiving the information from the satellites by parallel multi-channel design that determines its accuracy, it compares both the time that the signal was sent (each satellite has a built-in atomic clock) with the time that the GPS received the signal to calculate how far away the satellite is at the moment. The GPS then picks up the signal from at least three satellites to calculate its longitude and latitude. Once the receiver is able to figure out the user’s location, it then calculates the speed that the user is traveling by continually updating its position with the satellites, as well as calculating how far the user has traveled in a designated amount of time.

However, it doesn’t require the user to memorize long manuals. Still, a little understanding of its Multiple Global Navigation Satellite Systems (GNSS), Garmin Connect, and Garmin Explore app via tutorials and once over-read of manual available would suffice too. Since with a few days’ use, the user will be able to not only get the hang of it but also understand its capacity levels on a better note. The device also prompts users to use lithium batteries instead of alkaline to maintain temperature sensitivity.

What are the key features?

Amongst the GPSMAP 64 series, only the GPSMAP 66st is a turbocharged version. On its “t” model, the Garmin has included pre-loaded TOPO maps and the capability for downloading Birds Eye satellite imagery without the need for a subscription. With the MIL-STD-810G frame beefed up to meet the military’s requirement for the gadget to be shock and thermal resistant, the gadget ensures longevity irrespective of the jarring situations.

Aside from the impressively smooth and easy to use controls, the following are the features that make the gadget highly commendable amongst its rivals.


With a quad-helix design making the antenna quite sensitive and better than various low satellite angle designs, GPSMAP 66st offers excellent reception. The 66st further employs three different satellite systems, namely: GPS (North America), Galileo (EU), and GLONASS (Russia). Therefore, allowing the most amount of satellites for triangulation, making it a really accurate unit. Thus, maintaining precise location even in the heavy canopy of the forests and deep folds of canyons. 

Comprehensive Area Augmentation System and Parallel Multi-Channel Design 

There are certain atmospheric conditions that usually cause inaccuracies with a GPS receiver. Such include ionosphere and troposphere delays caused due to a slowing signal when the satellite passes through the atmosphere. The Garmin GPS system has a built-in measure to correct for this time-delay error, further improving its accuracy and reliability. Further enhanced by the PMC design, which enables the GPS System to lock onto a satellite signal when first switched on and to maintain that lock even when surrounded by tall buildings or trees so that the user doesn’t lose his way even in a field of junipers.

Global Navigation Satellite System (GNSS)

The Garmin GPSMAP 66st provides multiple Global Navigation Satellite Systems (GNSS) in order to support tracking the user’s route effectively, even in challenging environments that would otherwise prove difficult for GPS alone. Besides offering TOPO mapping, which includes parks and forests, terrain contours, elevation information, tracks, water bodies (river and lakes), and various points of interest.

Ease of Use 

With the large, easy-to-read labeled buttons, the GPSMAP 66st offers the most convenient usage right from the get-go. Unlike other units, the 66st buttons offer conclusive and straightforward instructions, with each having a distinct function in specific settings. Thus making the design sophisticated yet free of inconvenience. As the functions get more in-depth, the controls grow intricately complicated, which is unsurprising. While pairing with other devices and apps indeed involves a lot of back and forth registration and pairing hassle, it is, however, only a one-time inconvenience. 

Handy and Better User Interface Features 

  •      Recording controls: Offer direct and easy access to such an essential function by the ENTER key available.
  •      Power key: While opening a status page with functions like backlight control, Connect IQ widgets, Bluetooth status, the tool comes in handy
  •      Satellite page: Allows multiple and different views for each GNSS.
  •      Page ribbon: Located and visible at the lower part of the display.
  •      Trip computer: Pressing the + or – keys dynamically changes the number of data fields

Sensors (external) 

  • ANT+ (heart rate, cadence, speed, cadence/speed, temperature, chirp, VIRB, inReach Mini, XERO)
  • Bluetooth (heart rate, cadence, speed, cadence/speed)

Expedition Mode 

The 66st can be put in expedition mode to save battery life up to 170 hours compared to the 16 hour GPS mode on long trips. Even if soaked, knocked, or dropped, the 66st, however, never stops kicking. With the military built specifications, this thing is definitely rugged and impact-resistant. If you employ a lithium battery pack as suggested in the manual guide, the GPSMAP 66st will prove its worth in nearly any jarring environment.

Miscellaneous Services 

  • LED flashlight (SOS beacon)
  • Red flashing LED near the antenna (used often for expedition mode)
  • The inReach remote function for controlling your inReach Mini device which employs an Iridium Satellite Network system.
  • RINEX logging (L1 band)

Garmin GPSMAP 66st

Data Capacity:

With the following features complementing the data capacity,

  • 20,000 points per track-log
  • 250 saved GPX tracks
  • 300 saved FIT activities
  • 10,000 waypoints
  • 250 routes
  • No limit on geocaches (depending on the available memory)
  • 15,000 map segments

The Garmin GPSMAP 66st stands unrivaled amongst other units.


Being a highly versatile and accurate GPS unit, the GPSMAP 66st appears to be quite bombproof. The rechargeable NiMH battery pack, however, is simply two AA’s and is readily available around the globe. Lithium batteries instead of alkaline batteries make this gadget cold-resistant too. With the large buttons, it works excellent for ski touring, backpacking, fieldwork, or other wet and cold activities, and you name it. Thus making it appropriate for any handheld GPS situations an enthusiastic hiker could encounter.

Display Quality 

Employing a transflective TST display on a three-inch screen, the Garmin GPSMAP 66st offers a soft eye read even on snowy or bright sunny days. The absence of touch-screen and portrait view is not even essential to this gadget and therefore doesn’t lower its overall credibility. The 240 x 400-pixel display offers vivid photos or satellite imagery visuals on the Bird’s Eye function, which otherwise would have proven to be an eye squinting work to tell much of a difference in the route.

Garmin Explore App

When met with an offline situation and to top it off, no cell service too, the 66st automatically pairs with the in-built Garmin Explore mobile app to allow the user to plan their route or re-route the whole track, review and sync data including waypoints and locate new tracks. Furthermore, it allows the user to review completed activities while still engaged in the field and off the grid. Thus proving to be steadfast and handy in any uncalled and unforeseen situations.


The button-operated Garmin GPSMAP 66st is slightly lagging when it comes to competing against touch-screen GPS models. Still, it wasn’t slow to the point of creating any noticeable and critical issues. The 66st, however, draws out maps in a record time, enough for the maps to be redrawn almost as fast as dragging a pen across the map sheet, but depending on the scale. The 66st can further rummage through data quickly and doesn’t require painstakingly long seconds to load big route files or Birds. Eye satellite images even while re-routing.

Weight and Size 

At eight ounces, the 66st accounts to be the heaviest unit. On one note, the eight ounces don’t seem much. On a second note, it is half a pound, which sure is a lot when considering something closely sized to your cellphones. Fitting into most jackets does make it portable, but when hiking and having 66st in your pant pocket sure can be annoying. This unit is surely not meant for the hikers, who prefer to stay ultra-light while on a hike, out there but a somewhat practical and severe tool for researchers in gathering loads of information with its heap-holding-memory.

Garmin GPSMAP 66st


  • Brilliant display.
  • GPS accuracy & fast satellite reception.
  • Buttons with click feedback.
  • Comes with digital topographic maps of the U.S. and Canada.
  • Highly Compatible with three different satellite systems.
  • Improved interface.
  • Smart notifications and connectivity.
  • Full set of navigation features.
  • Wireless features.
  • IPX7 water-resistant.
  • Availability of maps.
  • Garmin Explore App available even offline.
  • Expanded wireless connectivity, which supports Active Weather feature.


  • Not such a good fit for small hands.
  • Disabling battery save mode is possible only by pressing the power key.
  • No two data field options available for the map page.
  • Offers an expensive GPS.
  • Buttons are located on the right instead of left, thus rendering it useless on a cruise with a clutch hand and being forced to take one of the hands-off from the throttle, which could prove distracting and life-threatening on rainy days.
  • The weight is on the heavier side of the range.
  • The power key is located near the GPS antenna, which proves difficult to use when functioning with one hand since it is a hassle to leave the battery save mode running, as this operation is only applicable by pressing the power key.
  • Complicated connectivity on devices, especially while using Wi-Fi and Bluetooth services.


Based on the following derived conclusions,

  •      GPS: 100%
  •      Battery: 60%
  •      Display: 100%
  •      Handling: 80%
  •      Navigation: 80%
  •      Features: 80%
  •      Maps: 100%

The Garmin GPSMAP 66st offers an unparalleled package on such a friendly budget. It holds more data than any GPS gadget, which a really dedicated and enthusiastic field researcher on a long trip could put to use, can connect to smartphones and Wi-Fi, and can view the world via maps or satellite imaging. The 66st isn’t exactly cheap, but you get your money’s worth, that is: a sturdy, accurate, trustworthy, featured GPS unit. Therefore, it hits the bullseye in terms of credibility, durability, and convenience.

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