The Casio ProTrek WSD-F30 is the improved version of the 2017 WSD-F20. It is the third generation of Casio's rugged ProTrek outdoor smartwatch, which runs on Google's Wear OS smartwatch operating system.

The F30 has been tested to meet the US military standard of ruggedness. It is water-resistant to a depth of 50m and can withstand temperatures as low as -10 degrees Celsius.

It has a built-in digital compass, barometer and altimeter - features not often seen in other smartwatches. In addition, it features offline maps.

In terms of design, the F30 does not differ much from its predecessors. It has a sturdy metallic watch case (available in black, blue and orange - the version tested) with a black resin bezel and black rubber strap. The strap feels very comfortable and features more holes for greater adjustment and fit.

On the watch case's left, there is a charging port and the barometric/altitude sensors. On its right, there are three buttons - the Tool (bottom), Map (top) and home/back (middle) buttons.

The F30's watch case is 1.2mm shorter, 3.9mm narrower and 0.4mm thinner than the F20's watch case. The F30 is also 8g lighter (inclusive of the watch strap). Nonetheless, the F30 is still big compared to other smartwatches in the market. And its rugged looks mean it is not a watch to wear to black-tie events.

The F30 continues to use the series' unique dual layer screen of monochrome (for just time-keeping) and colour (for smartwatch functions) LCDs, though its 1.2-inch screen is slightly smaller than F20's 1.32-inch (320 x 320 pixels) screen.

But the F30's display has a higher resolution of 390 x 390 pixels that shows maps in finer details. Furthermore, it is a full round touchscreen and no longer sports the "flat tyre" design (or the dark area at the screen's bottom) found in the F20.

Pressing the Tool button toggles the display for the digital compass, barometric readings, altitude readings and sunset/sunrise timings.

The digital compass pointed to the same North direction as my military compass, while the altitude readings were pretty much spot on. As usual, I drove to the peak of Mount Faber to get a reading. And I found the F30's readings to be around 112m - not far from Mount Faber's actual height of 105m.

Pressing the Map will activate a colour map of your location. While it took around 20sec previously for the F20 to load and show the map of the current location, it took less than 5sec with the F30.

You can mark the map with icons along a route. For instance, you can mark your start point with a star icon, so you know how to make your way back. You can also add a voice memo to remind yourself about a particular location you have marked.

Unfortunately, like its predecessors, the F30 lacks a built-in heart rate monitor that is standard in most new smartwatches. So you won't know how hard your heart is pumping when using the F30 to track your workouts. It is a shame, as the F30 could have doubled up as a fitness watch too.

In terms of steps tracking, the F30 counted around 8 per cent fewer steps than my calibrated Apple Watch Series 4. But it was more accurate in tracking my runs via GPS. On my usual jogging 5km route, its readings were only 100m less than the actual distance.

Battery life is rated at 1.5 days in smartwatch mode. However, in my tests with the watch constantly paired with a smartphone and with notifications turned on, the battery level dropped to 30 per cent only by the end of the second day. Pretty impressive.

You can also switch to the Multi Timepiece Mode, whereby it shows altitude and atmospheric pressure readings in monochrome mode but with a supposedly one-month battery life.

However, I am disappointed that the F30 still lacks solar-power capability, since it is targeted at the outdoorsman.

But the biggest downer is its price. At $749, it is on the high side, especially when an Apple Watch Series 4 smartwatch starts from $599.

Verdict: If you are looking for a rugged outdoor smartwatch, the Casio ProTrek WSD-F30 is a great choice. If not, there are cheaper and better options in the market.