If you like your watches complicated and your timezones varied, chances are you’re already aware of the Seiko Astron GPS Solar line, first launched in 2012. No, the watch doesn’t shout haphazard driving directions at you. Instead, its latest models use GPS technology and a solar-sensitive dial to automatically update the time according to your geographic position up to twice a day. But Seiko wasn’t done there—almost exactly a year on from the introduction of the Caliber 5X83, the first pairing of Dual-Time tech with a chronograph function, Seiko has unleashed four new Astron GPS Solar Dual-Time Chronographs.

Each of the four new watches—references SSH175, SSH177, SSH179 and limited-edition SSH180—features a titanium bezel with a sapphire crystal insert, adding a touch of practicality and elegance to the already robust profile of the Astron. An imposing 44mm mirror-polished titanium case houses the Caliber 5X83 movement, which promises a litany of advanced features, most prominent of which is the aforementioned GPS-controlled time and time zone adjustment. A world time function, perpetual calendar correct to the year 2100, automatic DST adjustment, AM/PM and signal reception indications, accuracy of +/- 15 seconds per month, and more round out the slate of functions. Of course, the titular chronographs also loom large on the dial, with a 1/20th second counter at 12 o’clock and a 12-hour counter with hours and minutes at 6 o’clock during chronograph operation. 

The three non-limited models feature super-hard coating on the titanium case and matching bracelets, 100m of water resistance, and 4,800 A/m of magnetic resistance, following the Astron lineup model of rugged capability. The bracelets additionally feature a three-fold clasp with push-button release, so you can slip each Astron off your wrist in record time. I find that such clasps add an unexpected level of class to a tool watch, and given the solar GPS functions, I can imagine taking a Caliber 5X83 off to place it on my dashboard or windowsill to get its twice-a-day sun treatment. A small thing, yes, but an added touch of comfort to an otherwise utilitarian design. 

Seiko hasn’t left style in the dust, though. Each model of the new quartet features a different color scheme; the SSH175 wears a blue dial and bezel with silver case, bracelet and accents, while the SSH177 replaces that blue with a more subdued black. The SSH179 shakes it up with a stealthy all-black dial, case, and bezel, with the chronograph subdials and other details in silver—my preferred combo of the non-limited trio. All four watches feature LumiBrite coating on the hands and indices, and a dual-curved sapphire crystal.

The SSH180 limited-edition model sets a dressier visual standard, with a black bezel and silver hour markers and hands ringed in gold. A dark blue dial with matching subdials ushers in a moody, suave appearance, and a stripe of black super-hard coating on the bracelet—which also features some ceramic parts—further elevates the profile of the SSH180. A limited-edition declaration and serial number are additionally engraved on the caseback. 

The four new Astron models are Seiko doing what they do best; affordable function with a dash of timeless styling. All four are slated for a May 2025 release—the SSH175 and SSH177 will retail for $3,100, and the SSH179 and SSH180 for $3,300. Seiko