The Citizen Promaster Sky Mechanical GMT – A Powerful, Accessible True GMT Watch

Created by Japanese watchmaker Citizen in 1989 as a brand to meet the needs of professionals working in the most challenging environments of the land, sea, and sky, Promaster has grown to a collection that includes over 30 different watches, all created with specific professional applications in mind. Celebrating its 35th anniversary this year, Citizen Promaster already released a very appealing edition of Challenge Diver. But that’s not all the brand had to show, as it also presented earlier this year its first Promaster mechanical GMT watch. And to be honest, for a first, it’s already quite a home run. Let’s have a closer look at this new Citizen Promaster Sky Mechanical GMT.

The concept of a mechanical GMT watch under the Citizen brand isn’t entirely new, as we’ve seen with the Series 8 880 Mechanical GMT. However, this combination of complication with an automatic movement is new to Promaster, the brand’s range of pro-oriented instrument watches. Created in 1989, Promaster finds its origin in the 1960s when Citizen started to manufacture timekeeping tools that could handle the challenges associated with underwater exploration, such as the acclaimed Citizen Seven Star – which has proven more than capable on the wrists of Japanese mountaineers climbing the north face of Eiger in the Swiss Alps in 1969. From the earliest days of the Promaster range, there have been watches with a focus on pilots – the Sky sub-range. But never the brand has made an automatic GMT, otherwise known as THE perfect pilot’s watch.

Problem solved this year with this watch, the reference NB6046-59E, also known as the Citizen Promaster Sky Mechanical GMT. What is it exactly? Does it live up to the respected Promaster name? Let’s find out… But you probably already understood from this article’s title that there’s something special going on here.

A highly powerful, ultra-robust and purpose-built tool. This is what makes me feel at first sight. Forget about refinement, compact proportions and vintage inspirations here. The Promaster Sky GMT is a proper modern instrument designed for a mission, made to impress and built to resist. Fully equipped, and fully ready for the job. You’ve been warned, it isn’t a watch that suggests things. Just like the Citizen Promaster Mechanical Diver 200m wasn’t designed for desk diving, this Promaster Sky isn’t made for flying in business class, but to be worn in a jetfighter cockpit. But since only a few of us will have that chance, let’s bring it back on land.

A true instrument pilot’s watch, the Promaster Sky GMT is made of stainless steel with most of the surfaces brushed, to avoid reflections. Its case is angular, mission-focused and offers protections on vital elements of the watch – crown guards are found on both sides. Thanks to a screwed back and a screw-down crown, the water-resistance is rated at 200m, rare on a pilot’s watch. A sapphire crystal protects the dial and both crowns have a fine knurled pattern for better grip, even with gloves. Finally, the bezel is dark grey coated for a bold contrasting look, with a rounded shape reminiscent of an aircraft fuselage. It is engraved with a 24-hour scale, offering immediate readability of the additional time zone function.

Let’s talk proportions… I’m not going to minimize things. The Promaster Sky Mechanical GMT is a large, heavy and sturdy watch. It wears and feels like an instrument, and would certainly feel even more appropriate if strapped on top of a flight suit. It measures 44.5mm in diameter, about 50mm in length and weighs about 175 grams. The 12.7mm thickness is acceptable considering other measurements. Photographed on Robin’s 18cm wrist, it’s not uncomfortable, on the contrary, but it exudes an undeniable presence.

As you have noticed, there’s an additional crown at 8 o’clock, which works together with the inner slide rule, adding even more pilot’s watch layer to this model. The rest of the dial is as straightforward as it could be, with large white painted and luminous hands, oversized luminous applied markers, a central crosshair and the all-important GMT hand proudly coloured in red. A date is found at 3 o’clock, a relevant feature for a dual-time watch. But what impresses more is the fact that we’re looking at a true GMT watch – the local time hand is adjusted by the crown in one-hour increments, not the GMT hand, a far more practical function when travelling. We don’t see this type of GMT watch often in this price range.

Under the caseback engraved with an image of a flight helmet is the in-house calibre 9054 (the same as used in the Series 8 880 Mechanical GMT). This automatic movement runs at a 4Hz frequency and stores 50 hours of power reserve when fully wound. It is regulated to run within a deviation of -10/+20 seconds per day but will often perform better. All functions are adjusted by the crown, including the important traveller’s function.

Worn on a large 22mm bracelet, which feels rather well integrated into the whole design, the Citizen Promaster Sky Mechanical GMT reference NB6046-59E is a truly impressive watch – in all senses of the word. It is robust, sturdy and powerful looking. It does leave this impression of a well-designed tool for a job, as a piece of gear should… But what’s also impressive is the list of features that it brings to the table for a very reasonable price of EUR 745. As said, it might be Promaster’s first mechanical GMT watch, but it’s not cutting corners.

For more details, please visit CitizenWatch-Global.com.