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Ulysse Nardin Blast: History of the Stealth-Inspired Sport Skeleton Watch

The Ulysse Nardin Blast , introduced at Geneva Watch Days in 2020 , is the brand's sport skeleton line — a 45mm avant-garde watch whose angular case architecture draws inspiration from the faceted geometry of stealth aircraft, specifically the Lockheed F-117 Nighthawk. The Blast is not a continuation of the Freak family but a parallel evolution of the Executive collection, replacing the Executive skeleton watches with a more aggressive, sport-oriented case language while retaining the brand's signature silicon movement technology. Its most immediately recognizable feature is the dual ceramic crown guard flanking the signed crown at 3 o'clock — the "blast shield" that gives the line its name and creates a protected crown architecture unlike any other watch in the current Swiss catalog. The signature blue-lacquered bridge variant, with its brilliant blue X-shaped bridges visible through the openworked case, is among the most photographed watch designs of the early 2020s.

Design Philosophy: Stealth Aircraft Geometry

The Blast's case was designed with explicit reference to the faceted, radar-absorbent geometry of stealth aircraft. The tessellated triangular lugs, sharp flat planes on the case flanks, and alternating polished, brushed, and sandblasted surface treatments echo the angular architecture that defines aircraft like the F-117 Nighthawk and the B-2 Spirit — designs in which every surface angle serves an engineering function rather than an aesthetic convention.

The crown guard is the Blast's most distinctive structural element. Two ceramic guards flank the signed crown at 3 o'clock, protecting it from lateral impact while creating the watch's signature silhouette. Ulysse Nardin refers to the proprietary shock absorber technology used in the movement — a single-piece silicium component called UlyChoc — which replaces traditional multi-part metal shock absorbers. This technology protects the movement's delicate balance wheel and escapement components from impact forces consistent with the sports watch positioning.

The Blast's skeleton architecture makes the internal movement visible through the case at multiple angles. The dual X-shaped structural bridges — one in sandblasted grey, one in brilliant blue lacquer on the signature variant — are not purely decorative: they function as mechanical clamping structures within the movement architecture. The blue lacquer is applied to the brass bridges before assembly, requiring careful sequencing of the finishing and movement assembly processes.

Blast Movements: UN-371 and UN-172

The Blast family uses two distinct calibres depending on the reference:

The Calibre UN-371 powers the 42mm Blast Skeleton X variant. It is manual-winding with 173 components, 21 jewels, 96 hours of power reserve at 21,600 vph (3 Hz), and features silicon components (balance wheel, escapement wheel, balance spring, anchor) that are identifiable by their characteristic purple-blue color. The UN-371 produces no tourbillon; the Skeleton X is a pure time-only manual skeleton at the more accessible price point of approximately $17,500–$21,500 in titanium.

The Calibre UN-172 powers the 45mm Blast Skeleton Tourbillon — the first Ulysse Nardin skeleton model with an automatic tourbillon. The UN-172 is automatic, with a platinum micro-rotor visible at 12 o'clock on the dial side. It includes a flying tourbillon at 6 o'clock, 137 components, 18,000 vph (2.5 Hz), and a 72-hour power reserve. The UN-172's flying tourbillon — where no upper bridge supports the tourbillon cage, making it appear to float — is visible from both dial and caseback. Both calibres carry the silicon technology lineage from the 2001 Freak, now delivered in the sport skeleton context.

The Blue Lacquer Variant: Blast's Signature Reference

The Blast's most recognizable configuration is the blue lacquer Skeleton Tourbillon — a titanium-cased 45mm watch in which the visible movement bridges are finished in brilliant blue lacquer. The blue X-shaped bridges, visible through the openworked case windows, create a stark color contrast against the grey titanium case and the purple-hued silicon components of the UN-172 movement. The combination — blue lacquer, silicon purple, titanium grey — is unmistakably a Blast at any distance. This reference (3603-260) became the Blast's visual identity from the line's 2020 launch and has remained the most widely published Blast variant in watch media.

Blast Tourbillon and Limited Editions

The Blast HourStriker Tourbillon is the most technically complex Blast reference: it pairs a flying tourbillon with a chiming complication — hourly and half-hourly strikes — using a partnership with audio technology company Devialet to optimize the acoustic performance of the chime. A DLC-coated titanium membrane (0.3mm) amplifies the mechanical hammer strike against the steel gong; the resulting tone is notably louder and more resonant than conventional repeater watches of similar case volume. The HourStriker represents the extreme of what the Blast architecture can accommodate as a complication vehicle.

Frequently Asked Questions

What is the Ulysse Nardin Blast?

The Blast is Ulysse Nardin's sport skeleton watch line, introduced at Geneva Watch Days 2020. It features an angular case design inspired by stealth aircraft geometry, dual ceramic crown guards, fully skeletonized movement architecture, and silicon movement technology. It is distinct from the Freak family — the Blast uses conventional hands, not the Freak's rotating movement.

Why is the Ulysse Nardin Blast called the "Blast"?

The name references the aggressive crown guard design — described as a "blast shield" — that protects the crown from impact. The case geometry was also inspired by the "blast" aesthetic of stealth aircraft and high-performance motorsport, with faceted angular planes replacing conventional rounded case shapes.

What movement does the Blast use?

The 42mm Blast Skeleton X uses the UN-371 manual-winding calibre (96-hour power reserve, silicon components). The 45mm Blast Skeleton Tourbillon uses the UN-172 automatic (flying tourbillon, platinum micro-rotor, 72-hour power reserve, silicon components). Both carry silicon movement technology descended from the 2001 Freak.

How much does the Ulysse Nardin Blast cost?

The entry Blast Skeleton X in titanium starts at approximately $17,500–$21,500. The Blast Skeleton Tourbillon (45mm) runs EUR 44,000–46,000. The Blast Tourbillon Blue & Gold (two-tone titanium/rose gold) is CHF 63,500. The Blast HourStriker Tourbillon (chiming) is approximately CHF 99,000.

Is the Blast related to the Freak?

No — the Blast and Freak are distinct collections. The Blast evolved from the Executive line and uses conventional hands for time display. The Freak's defining feature — the rotating movement carousel that replaces hands entirely — is not present in the Blast. Both share the brand's DIAMonSIL silicon escapement technology, but serve different design and mechanical philosophies.

Sources: Ulysse Nardin (ulysse-nardin.com), Monochrome Watches, aBlogtoWatch, Fratello Watches, Hodinkee.