The name Pro Trek replaced the original Pathfinder moniker in 2011 and while I personally liked the latter — Pro Trek aptly describes Casio’s line of wristwatches that are synonymous with hiking, climbing, camping, and the outdoors.

We previously tested two Pathfinder models, one at the top of Loveland Pass and another in Denver. And despite the name change, Casio’s accessibly-priced multi-sensor outdoor tool watch still provides all of the original functions it did when we first got our hands on one almost a decade ago — but now with the addition of more sensors and with an app for advanced control of the watch via Bluetooth wireless.

Casio Pro Trek PRT-B50

For this review, we tried out the Casio Pro Trek PRT-B50-1 with Quad Sensor and Smartphone Link technology (and photographed it outside as well as in the studio) over a period of two months.

Outdoor shot water leaves moss

With the line’s signature black/yellow styling and over-engineered design, this Pro Trek is made for outdoor enthusiasts who want manual control and reliability meshed with the convenience of smartphone connectivity but without the nuisance of a touchscreen. The Pro Trek PRT-B50-1 is also available in a blue version and orange/black)

Casio Pro Trek PRT-B50 top down

Casio also makes the Pro Trek Smart that we went hiking with if you’re interested in a full-blown smartwatch with colored GPS maps, a built-in music player, and so forth —  and if you don’t mind charging it daily. Thankfully, the PRT-B50 requires no charging and has a battery that lasts approximately 2 years. You still get many of the functions with less reliance on a smartphone and cellular signal and no need whatsoever for a power outlet.

Casio Pro Trek PRT-B50 wristshot

Like all of the Pro Trek line, the case is substantial, measuring 50 mm across, 57 mm lug-to-lug, 16 mm thick, and 22 mm in between the lugs. It also has huge buttons, with a knurled texture on the side buttons. This is all by design so the watch can be operated even when hanging off a cliff face with gloves on, or while hiking in freezing temperatures where taking your gloves off is not really an option.

Casio Pro Trek PRT-B50 wristshot

Even considering the dimensions, the case is crafted out of lightweight resin and weighs a mere 64.2 grams, which is the approximate weight of a small vintage watch. By comparison, a modern stainless steel watch can easily weigh over 150 grams, especially with a metal bracelet. Considering the purpose, this weight is optimal because you don’t want to be bogged down by extra weight, whether climbing or hiking. However, with that said, it brings me to one caveat. The case is made of resin so it’s going to get scratches and dings pretty easily compared to stainless steel. At the same time, if Casio did make the Pro Trek in an elevated stainless steel version, paradoxically, the price would go up along with the weight.

Casio Pro Trek PRT-B50 pocketshot

The dial is protected by an armored mineral crystal which means it sits below the plane of the bezel and is therefore protected by most things bumping it. A mineral crystal scratches easier than the more expensive sapphire crystal you see on luxury wristwatches but it’s also more durable against shattering and can be polished to a certain degree whereas if a sapphire gets hit hard enough it shatters. For a watch made to be banged around outdoors, a mineral crystal is the most practical choice.

Casio Pro Trek PRT-B50 side

The watch bezel has a bidirectional compass scale that you align with the red arrow-tipped second hand when the watch is in compass mode. Once the second hand is pointed bearing North you can align the bezel and use the watch as a compass. The watch simultaneously gives you a compass reading in degrees on the digital display. Further, in a pinch, with this watch, or any watch with a centrally mounted 12-hour analog hand, you can hold the watch up and visually align the hour hand with the sun and then look halfway between that and 12 o’clock to get a South bearing, at which point you can align the bezel accordingly. Additionally, a location indicator allows users to operate the watch buttons to save their current location in the app. In this mode, the compass bearing of the saved location point is indicated by the second hand of the watch and the distance is indicated on the LCD.

Casio Pro Trek PRT-B50 dial detail

Thanks to a dual illumination system the dial can easily be read in any low-light situation. First, the hour and minute hands are treated with a traditional white luminescent paint like you find on traditional wristwatches that are charged by sunlight and that emits a green-blue glow. Second, there’s a dual-LED backlight that is activated by pressing the large yellow button. Unfortunately, the Arabic numeral and indices do not have any luminescent paint which does make reading the hour and minute a bit harder in the dark, although a simple press of the LED button fixes that.

Casio Pro Trek PRT-B50 lume and light shot

The Pro Trek PRT-B50 displays hours, minutes( hand moves every 10 seconds to conserve power), and seconds via analog hands which are driven by a battery-powered quartz watch movement (module 5601). The time is set automatically and adjusts 4 times per day when the watch connects to the app to automatically download global time updates, however, even without a mobile link connection the watch is still accurate to ±15 seconds per month, according to Casio. The automatic time setting feature also includes time zone changes as well as Daylight Saving Time (DST) recognition by country. The time rules are stored on the watch to automatically adjust the time based on the latest data.

Casio Pro Trek PRT-B50 button detail

As mentioned above, Pro Trek is an evolution of the Pathfinder line and accordingly, it utilizes four separate sensors to individually detect compass bearing, barometric pressure ( hPa and inHg – toggled in the app)/altitude (feet or meters – toggled in the app), temperature (Fahrenheit or Celsius – toggled in the app), and acceleration. The latter is the newest sensor seen within the Pro Trek line and is used for counting steps, which in turn is used in the calculation of calories burned. Notably, the Quad Sensor system uses compact sensors that make it possible to pack all of these instruments in a relatively compact wrist-worn device.

Casio Pro Trek PRT-B50 hanging on cliff face

The most technologically advanced feature of the Pro Trek PRT-B50 is the Smartphone Link functionality which enables the timepieces to connect (via Bluetooth®) to the Pro Trek Connected app and collect useful data measured by the sensor and store it on the app to support outdoor activities, as well as control settings on the watch. The app is available for iOS and Android phones.

Casio Pro Trek PRT-B50 button detail

Built-in sensors and wireless connectivity to the Pro Trek app add a plethora of high-tech functionality. There’s a route log where the app automatically records altitude data from the watch and GPS data from the smartphone. Users can also manually acquire altitude data at any point and plot that point on the route. The data can be viewed as a route map on the app, which is one of the coolest features.

Pro Trek Connected App Screenshots
Pro Trek Connected App Screenshots. Photo by Casio.

You can perform a watch button operation to record your current location in memory. Then after you move to a different place, a Location Indicator will point to the direction and display the distance back to the registered location. This makes it easy to determine the relationship between the two locations, which is an essential capability for outdoor activities.

Casio Pro Trek PRT-B50 sitting flat on rock

One feature that’s become immensely popular in recent years due to smartwatches such as Casio’s Pro Trek Smart, the Apple Watch, and of course dedicated fitness bands like the Fitbit which show calories burned as calculated based on step count and altitude data (to figure in upgrades and downgrades), which the app can display and save as part of the activity log. Altitude measurement values on the watch are automatically adjusted based on altitude data acquired from the smartphone GPS. And even without the app connected, you can, of course, call up the altitude at any time by pressing the button on the case at 4 o’clock which utilizes the watch’s built-in altimeter sensor and displays the result on the LCD screen.

Casio Pro Trek PRT-B50 wristshot

Interestingly, there are customization features within the app that allow users to turn the watch modes on or off and change the sequence in which the modes appear on the display. This allows users to customize the display for specific uses — for instance, showing only certain functions or changing the sequence to show frequently used functions first. The default content on the LCD can also be customized.

Casio Pro Trek PRT-B50 hanging on cliff face

A truly contemporary feature made possible by the Connected app is the ability to use the watch to trigger an audible alert on a mobile phone that’s been paired with the watch even if it’s set to silent mode. The tone is forced to sound even if the phone is in vibrate mode. This helps in locating a misplaced phone.

Casio Pro Trek PRT-B50 wristshot

The strap is 22 mm in width at the lugs and does not taper. A steel pin and buckle and a single rubber keeper (made to look like two keepers) keep the watch in place. Like many of the resin-based straps we’ve seen in the past, this one will presumably last a long time. However, when I feel certain softer rubber/silicone straps that are super soft and pliable, I know I would trade comfort for long-term durability, especially when the cost to replace them is negligible anyway. Resin straps are going to have a firmer feel than rubber straps. These straps are not the integrated type and they have quick-release spring bars, so you can effortlessly swap either factory or third-party straps with a standard quick-release system. This is awesome because if you don’t like the strap it comes with you can replace it with virtually any strap that’s 22 mm wide.

Casio Pro Trek PRT-B50 caseback

In addition to all the new Connected features, you still get classic Casio functionality such as a 1/100th of a second digital stopwatch, a sunrise sunset time display, a countdown timer, 5 daily alarms, an hourly time signal, 12/24 hour format, digital display of (hour, minute, second, am/pm, month, date, day), 38 time zones (38 cities + coordinated universal time), and daylight saving on/off. One of the most useful travel features of this watch is Home city/World time city swapping between the analog hands and digital display via the app.

Casio Pro Trek PRT-B50 wristshot


The case is 50 mm wide x 16 mm tall which is by no means small, but much of the that’s by design and required to accommodate all the sensors and functions. Thankfully the watch is incredibly light and well-suited for outdoor trekking. With a retail price of $220 this is the most affordable Pro Trek in the collection — yet thanks to its smart connected functionality coupled with analog hands and basic CR2025 battery — it’s also perhaps the most utilitarian pathfinder Casio’s created to date.

Learn more at Casio.

Casio Pro Trek PRT-B50 top down view

Posted by:Jason Pitsch

Jason is the founder of Professional Watches and specializes in writing, product photography, and digital marketing.