As you may have read on Fratello before, Seiko is celebrating the 100th anniversary of having this brand name on its watches’ dials this year. The house is introducing limited anniversary editions of new models throughout the year to commemorate this. Today, the Astron line sees a big new release, including an anniversary LE.

These are the Seiko Astron SSH151, SSH153, SSH155, and the limited SSH156. So, what’s new? Well, they mark the first time that Seiko has combined the Astron GPS Solar Dual-Time technology with a chronograph. This is thanks to a brand-new caliber, the 5X83. Let’s have a closer look!

Seiko Astron GPS Solar Dual-Time Chronograph SSH151 and SSH153

The new Seiko Astron caliber 5X83

The new caliber 5X83 features sub-dials at 6, 9, and 12 o’clock. To mechanical-watch enthusiasts like me, that triggers fuzzy Valjoux 7750 feelings. But this is no workhorse mechanical chronograph by any stretch of the imagination. This is a GPS-connected, solar-powered caliber that showcases Seiko’s continued evolution under the Astron line. And it packs some nifty features.

Seiko Astron GPS Solar Dual-Time Chronograph SSH153

The caliber connects to the GPS network twice daily or at the wearer’s request. It shows the main time in the center and an additional time zone at 6 o’clock. The user can swap these by holding down the two pushers for three seconds. For those familiar with the old 5X53, that swap now happens much more quickly than before. The sub-dial at 6 o’clock also becomes the minute and hour totalizer when the chronograph is running.

At 12 is a sub-dial that displays chronograph elapsed time in 1/20th of a second. The dial at 9 o’clock shows chronograph engagement, charging status, in-flight mode, and the day of the week. Lastly, you will find an AM/PM indicator and a date window between 4 and 5 o’clock. Of course, all the above is solar powered via the dial.

Seiko Astron GPS Solar Dual-Time Chronograph SSH151 on wrist

The Seiko Astron GPS Solar Dual-Time Chronograph SSH151, SSH153, and SSH155

The new caliber is debuting in three regular-production models — the SSH151 (black dial), SSH153 (silver dial), and SSH155 (black dial and black-coated case and bracelet). All three are, of course, made of titanium with an ultra-hard coating. The cases measure 43.3mm across by 13.4mm thick, and the semi-integrated bracelet fastens with a folding push-button clasp with an easy-adjust mechanism.

On top, we find a double-curved sapphire crystal with Seiko’s super-clear coating. These watches are pressure resistant up to 10 bar and can resist magnetism up to 4,800 A/m. The bezels consist of a top ceramic layer on a titanium base. The three regular-production models feature a 60-minute scale on the bezel in five-minute gradations.

Of course, you buy a Seiko Astron for its advanced functionality. As mentioned, you get a solar-powered dual-time complication as well as a chronograph. The time also automatically adjusts as you move through time zones. There is even an indicator to show when the signal is lost. Without GPS, you still get an uncorrected accuracy of ±15 seconds per month. You also get a perpetual calendar that is accurate until the year 2100. In short, there is plenty of tech on board!

Seiko Astron GPS Solar Dual-Time Chronograph SSH156

The limited anniversary edition, ref. SSH156

Then, there’s that limited edition I alluded to earlier. This is the SSH156 in black ultra-hard-coated titanium with gold accents. The main hands, decorative rings around the sub-dials, the Seiko logo, chronograph pushers, and the lower layer of the bezel are all executed in a gold color. In contrast to the standard models, the ceramic top bezel is faceted and does not feature any markings.

Seiko Astron GPS Solar Dual-Time Chronograph SSH156 close-up

The case back of the anniversary model is also different and has a gold-tone coating. It features Kintaro Hattori’s name, which you will surely recognize as that of Seiko’s founder. There is also the old “S” logo for the Seikosha factory and Hattori’s creed, “One step ahead of the rest.”

This limited model will come in a special presentation box with a metal “S” pin and an additional strap. You can swap the titanium bracelet for this high-strength silicone strap.

Pricing and availability of the new Seiko Astron GPS Solar Dual-Time Chronograph models

The new Seiko Astron SSH151 and SSH153 have a price of €2,600, while the black-coated SSH155 comes in at €2,800. Finally, the SSH156 is priced at €4,000. This one is limited to 1,000 units worldwide. The three other models are regular additions to the collection. All will be available starting today through the Seiko website, Seiko boutiques, and select Seiko dealers.

What do you think of these new Seiko Astron GPS Solar Dual-Time Chronograph models? Let us know in the comments below!

Watch specifications

Astron GPS Solar Dual-Time Chronograph 5X83
SSH151 / SSH153 / SSH155 / SSH156
Silver or black with sunray finish and applied indices with Lumibrite
Case Material
Hard-coated titanium (with black finish for SSH155 and SSH156)
Case Dimensions
43.3mm (diameter) × 13.4mm (thickness) for regular-production models / 43.3mm × 14.1mm for the limited edition
Curved sapphire with super-clear coating
Case Back
Titanium, screw-in
Seiko 5X83: solar-powered quartz caliber with GPS-controlled time and time-zone adjustment, accuracy of +/-15 seconds per month (without receiving a GPS signal and at temperatures between 5°C and 35°C)
Water Resistance
10 bar (100 meters)
Semi-integrated bracelet, folding push-button clasp with easy-adjust mechanism, additional silcone strap for SSH156
Time (hours, minutes, seconds) second time zone with AM/PM indicator, chronograph (1/20th-second counter at 12 o’clock, combined 12-hour/60-minute counter at 6 o’clock during chronograph operation), perpetual calendar correct to the year 2100, automatic DST adjustment, high-speed time-zone adjustment, time-transfer, signal-reception indicator, world time (38 time zones), power-saving mode
€2,600 (SSH151, SSH153), €2,800 (SSH155), €4,000 (SSH156)
Special Note(s)
SSH156 limited to 1,000 pieces