Ulysse Nardin Blast

Introduction

The Ulysse Nardin Blast is not a watch that whispers. With its aggressive ‘X’ skeleton architecture and a case carved from lightweight titanium, it announces itself as a modern horological statement. But the question for the daily-wear collector is not whether it looks good in a display case — it’s whether it can handle a Monday morning commute, a Tuesday client lunch, and a Wednesday gym session without feeling like a burden on the wrist.

I’ve spent a full week with the reference 1725-400/02, the black DLC titanium version with a matching black alligator strap. This is the Blast stripped of any pretense: no tourbillon, no chronograph, just a pure skeletonized automatic with a date. And that’s exactly what makes it interesting. At 45mm, it’s large, but the titanium construction and thoughtful ergonomics make it far more wearable than its diameter suggests. Let’s break down what survives a real week on the wrist.

Manufacture History

Ulysse Nardin was founded in 1846 in Le Locle, Switzerland, and built its reputation on marine chronometers — precision instruments for navigation. The brand’s modern renaissance began in the 1990s with the Freak, a watch that reimagined the movement as the dial. The Blast line, introduced in 2020, continues that avant-garde spirit with a skeletonized architecture that pays homage to the brand’s maritime roots through its ‘X’ motif, reminiscent of a ship’s rigging.

Movement

At the heart of the Blast is the in-house caliber UN-172, an automatic movement with a silicon escapement and a 72-hour power reserve. It’s COSC-certified, meaning it’s been tested for accuracy in five positions. The movement is fully skeletonized, with bridges shaped like an ‘X’ that create a dramatic open-worked dial. The finishing is excellent for the price: circular graining on the mainplate, perlage on the bridges, and beveled edges that catch the light. The date is displayed at 6 o’clock via a small window integrated into the lower bridge — a neat design touch that doesn’t disrupt the skeleton aesthetic.

Specifications

• Case Diameter: 45mm
• Case Thickness: 13.5mm
• Lug-to-Lug: 52mm
• Case Material: Titanium with black DLC coating
• Crystal: Sapphire with anti-reflective coating
• Water Resistance: 100 meters
• Lume: Super-LumiNova on hands and hour markers
• Strap: Black alligator leather with rubber lining
• Clasp: Deployant buckle in titanium

Wrist Feel

Despite the 45mm case diameter, the Blast wears surprisingly well thanks to the titanium construction. The entire watch, including the strap, weighs just under 100 grams — light enough that you forget it’s there during a long day. The lug-to-lug of 52mm is manageable for a 6.75-inch wrist, though the angular lugs do extend a bit. The rubber-lined alligator strap is supple out of the box and the deployant clasp distributes pressure evenly. The skeleton dial lets light pass through, which actually reduces visual bulk; the watch feels more like a floating X than a solid block. The only minor comfort issue is the crown — it’s large and slightly sharp-edged, occasionally digging into the wrist during push-ups or wrist flexion. But for daily desk duty and casual wear, it’s a non-issue.

Accuracy

Over a week of mixed wear (office, gym, sleep), the UN-172 ran consistently at +3.5 seconds per day, well within COSC spec. The silicon escapement ensures magnetic resistance and long-term stability. Day-to-day variation was minimal — never more than ±1 second from the average. For a skeleton watch with so much open space, the balance wheel remains well protected and the amplitude stayed strong even after 60 hours off the wrist.

Occasions

The Blast is versatile enough for daily wear, sporty enough for casual outings, and dramatic enough for formal events. The black DLC case and alligator strap dress up nicely under a cuff, though the 45mm diameter may be too large for a tight dress shirt. It’s also a capable travel watch thanks to the 100m water resistance and robust movement.

Wrist Presence

4.5/5 — The skeleton X dial and black DLC case create a dramatic, architectural look that draws attention without being gaudy. It’s a conversation starter, but the matte finish and dark tones keep it from being a flashy peacock.

Reference Variants

The Blast line includes several dial and case options. The 1725-400/00 features a blue skeleton dial with blue PVD bridges. The 1725-400/01 has red accents on the X bridge and seconds hand, paired with a rubber strap. The 1725-400/03 is a rose gold version with a brown alligator strap. All share the same UN-172 movement and 45mm case.

Family References

Other models in the Blast family include the 1725-400/00 (blue), 1725-400/01 (red accents), 1725-400/03 (rose gold), and 1725-400/04 (white gold).

Other Notable Models by Ulysse Nardin

The Freak X is a more radical skeleton with a carousel tourbillon, while the Diver X Skeleton offers a similar open-worked dial in a dive watch case. The Marine Torpilleur is a more traditional dress watch for those who prefer classic elegance.

Similar Watches

If you like the Blast, consider the Hublot Big Bang Unico Skeleton for a similar aggressive skeleton in ceramic, or the Zenith Defy Skyline Skeleton for a more integrated bracelet design. The Richard Mille RM 011 is the ultimate high-end skeleton, but at a much higher price.

Homages

For a budget-friendly skeleton with an X-shaped bridge, the Stuhrling Skeleton 40 offers a similar look for under $200, though with mineral crystal and lower water resistance. The Invicta Pro Diver Skeleton is another option, but lacks the refinement of the Blast.

Investment Value

The MSRP of the Blast ref. 1725-400/02 is $24,500. Pre-owned prices range from $15,000 to $20,000, making it a stable investment. It’s not a limited edition, so don’t expect rapid appreciation, but the titanium skeleton holds value well among enthusiasts. Buy pre-owned to avoid the steepest depreciation.

Service Interval

Ulysse Nardin recommends service every 5 years. The cost is approximately $900, and service must be done by an authorized center due to the silicon escapement and skeletonized movement complexity.

Pros and Cons

Pros

• Lightweight titanium case makes the 45mm diameter wearable
• In-house UN-172 movement with silicon escapement and COSC certification
• Striking skeleton design that remains legible
• 100m water resistance is practical for daily wear
• Supple alligator strap with comfortable deployant clasp

Cons

• Crown can dig into the wrist during active movement
• No quick-adjust on the deployant clasp
• Date window is small and slightly recessed
• Lume is only on hands and hour markers, not on the skeleton bridges
• Pricey for a time-only skeleton without a tourbillon

Final Verdict

The Ulysse Nardin Blast ref. 1725-400/02 is a genuine daily-wear skeleton that doesn’t sacrifice comfort for drama. The titanium case and thoughtful ergonomics make it a watch you can actually live with, while the UN-172 movement delivers reliable timekeeping. If you want a skeleton that turns heads without demanding a second mortgage, this is one of the best options under $25,000.