Description
De Bethune has done it again — quietly. Without the marquee fanfare of a brand-new caliber and without the Watches & Wonders show-floor crowds, the Maison has dropped a fresh execution of one of independent watchmaking's most distinctive compact tourbillons: the DB28XS Sea Tourbillon. Where last year's DB28XS Kind of Blue Tourbillon argued for the colour, the new Sea Tourbillon argues for the movement of the colour — a hand-engraved random guilloché pattern across heat-blued titanium bridges that captures the gentle, irregular roll of waves on a calm sea.
It's the second iteration in De Bethune's emerging "art-on-the-bridge" series for 2026, following the Starry Seas. And while the calibre underneath — the in-house DB2009V7 with its 0.18-gram titanium tourbillon cage and 5-day twin-barrel reserve — is unchanged, the visual language is: this is a watch where the bridge has graduated from supporting cast to lead actor.
For collectors who buy De Bethune for the dial-side mechanical theatre rather than for marquee complications, the Sea Tourbillon is the new must-see piece — and one of the few high-end tourbillons in production where every example is, in a meaningful sense, visually unique.
Design
The DB28XS case architecture is by now instantly recognisable: 38.7mm × 8mm of mirror-polished grade 5 titanium, with the patented floating lugs that follow the wrist's curvature regardless of strap thickness, and the crown perched at 12 o'clock — a configuration De Bethune originally borrowed from pocket-watch tradition and made into a brand signature. The peripheral hour ring carries the brand's blued microlight engraving, a hand-applied surface of dense micro-grooves that scatter light in tiny, controlled flashes.
The new visual centre of gravity is the heat-blued titanium delta-shaped bridge — combining the barrel cover and the central triangular bridge into one continuous surface — onto which De Bethune's artisans hand-engrave a non-repeating, freehand sea-blue guilloché pattern. The waves run irregularly across the bridge surface, never duplicating from one watch to the next. Polished openworked titanium hour and minute hands sweep above; at 6 o'clock, the 30-second tourbillon is held in place by an openworked blued titanium bridge, the cage's two-rotations-per-minute pace just slow enough to register as motion without becoming a distraction.
Specifications
- Reference: De Bethune DB28XS Sea Tourbillon
- Case: 38.7mm diameter × 8mm thickness, grade 5 mirror-polished titanium, patented floating lugs, crown at 12 o'clock
- Crystal: Sapphire with double anti-reflective coating; sapphire display caseback (also double AR)
- Dial: Heat-blued titanium delta-shaped bridge with hand-engraved random sea-blue guilloché; peripheral titanium hour ring with blued microlight engraving; polished openworked titanium hands
- Movement: De Bethune calibre DB2009V7 — in-house, hand-wound, 239 parts, 33 jewels
- Frequency: 5 Hz (36,000 vph)
- Power reserve: 5 days (120 hours), via twin self-regulating barrels
- Tourbillon: 30-second tourbillon at 6 o'clock; 0.18g titanium cage with 63 components, two revolutions per minute
- Escapement: Silicon escape wheel; titanium balance with white-gold inserts; De Bethune flat-terminal balance spring; triple pare-chute shock absorber
- Water resistance: 30 metres
- Strap: Extra-supple alligator leather with alligator lining; polished titanium pin buckle
- Price: CHF 170,000
- Availability: Currently in production; no public limited-edition cap announced
What's Exciting
The DB2009V7 calibre is a known quantity — a refined, manual-wound 5 Hz tourbillon with a 5-day reserve and one of the lightest cages in production at 0.18 grams. Nothing about that is new in the Sea Tourbillon. What is new is how De Bethune is treating the bridge: as a hand-decorated artwork that carries the watch's identity. Random guilloché is harder to do well than it looks. A repeating geometric pattern is easy to fake by machine; a freehand pattern that has to look organic, never crowded, never clumsy, demands an artisan who has internalised what waves actually do. De Bethune has very few peers in this discipline — Voutilainen and Greubel Forsey work in adjacent territory, but at very different price points.
And at CHF 170,000 the Sea Tourbillon is a genuine value play within independent tourbillons: a fully in-house 5 Hz, 5-day, 30-second tourbillon caliber, in titanium, with hand-engraved bridges and a unique-per-piece dial finish. Comparable independents start north of CHF 250,000 and go up sharply from there.
History
The DB28 case architecture dates from 2010 and quickly became De Bethune's most identifiable silhouette: floating lugs derived from spring-loaded shock-mount engineering, the delta-shaped central bridge that gestures toward Star Trek's Starfleet Commando insignia, and the at-twelve crown that frees the dial from the visual asymmetry imposed by a side crown. The DB28XS ("extra small") variant arrived in 2023 to compress the proportions to 38.7mm; the related ultra-thin DB28XP followed.
The random guilloché bridge technique itself was first used on the limited-production DB28XS Starry Seas, where it evoked a starry sky. With the Sea Tourbillon, De Bethune brings the same hand-engraving discipline into the regular tourbillon catalogue and re-uses the visual language for water rather than sky — a clever extension of the technique that justifies it as a permanent collection piece rather than a one-off.
