Angelus U51 Diver Tourbillon

Angelus U51 Diver Tourbillon – Perfection in a diver piece?

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Angelus U51 Diver Tourbillon was presented this year at Baselworld. The high-tech piece uses modern design and manufacturing techniques. Its “tech” charm is doubled by a good looking appearance. The Angelus U51 Diver Tourbillon has real diver watch capabilities: unidirectional diver bezel set by an external crown, Helium escape valve and crowns protection.

U51 Diver Tourbillon soldat
A skeletonised movement with tourbillon in a sports diving watch

Hands-on review Angelus U51 Diver Tourbillon

I was always fascinated by the Angelus watches. U51 and its predecessor U50 made no exception. I have met the U51 Diver Tourbillon in the flesh during the Basel show. Before I share with you some watch description and specifications, please have a look at the video below.

The case: two interpretations

The high-performance sports watch look starts with the case. The case is manufactured in titanium. The size is generous – 45mm. But is was surprised by how good it looks on my small wrist and how comfortable and pleasant feels. I consider that the 12.47mm thickness helps a lot in this smaller wear sentiment.

U51 on the table
An unusual design but extremely good looking

The case is rich in details. The diver’s case is adorned with sandblasted, brushed and polished surfaces. Considering how complicated is to get multiple finishes on titanium, Angelus gets my full respect for design and implementation.

The bezel is carved with an interesting pattern. Not sure if “pattern” is the right word in this case but certain is that the final shape reminds me of two things: the sea waves and the ratchet wheel design. So two interpretation: a romantic one – the infinite number of waves breaking at the shore and the ratcheting wheel that permits movement only in one direction – onto the future. Leaving the romanticism aside, the case design is beautiful: technical and aesthetical.

U51 case side
The crowns’ side of the case where the multiple finishes can be easily observable

The U51 Diver Tourbillon has two crowns. The two o’clock crown is for the unidirectional 60minutes bezel. The four o’clock crown is a classic winding and set type. Both are screwed-in, as it is mandatory for a diver watch. The crowns are decorated with the Angelus logo and have good tactile feedback.

U51 crowns
The crowns are protected by subtle bumpers. The crown protection is smartly integrated into the over all design

On the left side of the case, at 9 o’clock, the watch is fitted with a Helium escapement valve. The U51 Diver Tourbillon is specified for 300m/1000feet depths. The valve is nicely integrated in the case design. The valve is protected by two bumpers.

U51 He escape valve
The side case with visible Helium escape valve

The skeletonised lugs contribute to the watch’s lightweight. Angelus fitted the diver with a blue rubber strap decorated with an embossed Angelus logo and a titanium folding pin buckle.

The titanium pin buckle with brand's logo
The titanium pin buckle with brand’s logo

Dial: colourful and joyful, with an expected total legibility

The U51 offers an unusual diver display, with the remark that the skeletonized composition and construction is the trademark of Angelus. The brand’s language is recognisable without a doubt in the person of the U51 Diver Tourbillon.

The "face" of the U51 Diver Tourbillon
The “face” of the U51 Diver Tourbillon

The dial is governed by several entities, each with its unique form and factor.

Another viewing angle of the dial
Another viewing angle of the dial

The chapter ring features the same spectacular carving as the bezel, recalling the waves. The unidirectional rotating ring dresses up with bright colours. The brand names them stormy blue and striking orange. Good names, I would say…

The blue and orange coloured chapter ring
The blue and orange coloured chapter ring

The chapter ring is governed by the brand’s logo at twelve o’clock. The indexes use Arabic numeral in 5 minutes increments. In addition, there are Super-Luminova filled indexes.

The small seconds complication
The small seconds complication with orange Super-Luminova filled hand

The hands are another distinct elements in this set of entities. The hands also use bright colours Super-Luminova filling: orange for the hour hands and white for the minute hands. In low light, the dial spoils us with a special performance – excellent legibility.

A low light wristshot
A low light wristshot

As a diver watch, the U51 is provided with running seconds, mandatory to a diver watch as a witness of watch’s functionality. The small seconds sub-dial is placed at nine o’clock. The seconds’ hand is filled with orange luminescent, to signalise the “running seconds”

One-minute flying tourbillon

The last of the entities set is the one-minute flying tourbillon.

Calibre A-310 – a mechanical delight

Angelus U51 Diver Tourbillon is powered by the high-tech Calibre A-310. The hand-wound movement is capable of 5 days of autonomy. The single barrel design is depleted by the tourbillon at a rate of 28,800 vibrations per hour. Or 4Hz – as it is otherwise known.

The back of the U51 reveals the other side of Calibre A-310
The back of the U51 reveals the other side of Calibre A-310

The tourbillon is positioned on the dial at seven o’clock. Its construction is interesting. The cage uses ball bearing for better stability. That is a more complex construction as the classical pivots system but comes with certain advantages.

Another view of the Calibre A-310
Another view of the Calibre A-310

The flying tourbillon is appealing: an overall mirror polishing and bevelled edges enriched with fine polishing.

The tourbillon cage is nicely decorated
The tourbillon cage is nicely decorated

The skeletonised movement is well decorated. The bridges and the mainplate’ surfaces are sandblasted. This finish highlights the natural aspect and colour of the titanium. The movement’s gear train uses the six-spoke design exclusive to Angelus. The beauty of the Calibre A-310 can be observed on both sides of the watch.

The back side of the U51 Diver Tourbillon
The backside of the U51 Diver Tourbillon

Designed for perfection, entitled for admiration

I have to admit that I like Angelus U51 Diver Tourbillon a lot. The watch features not only impressive technical details but also an unexpected appearance.

Tourbillon on a diver watch? Why not?!? One can enjoy a fantastic tourbillon watch daily and use it as a sporty tool piece. I do enjoy the funny, joyful glance of the U51. The colour theme fits unexpectedly well on this tourbillon watch.

U51 Diver Tourbillon is a bliss on the wrist. Extremely light for its dimension, due to titanium construction, the watch feels right on the wrist. I consider it such a special piece that breaks the canonical rules. Honestly, I would wear this piece anywhere. I would even take it, as it is, to a black-tie event. And if someone looks badly at my wrist. I will know for sure that is just envy. Pure envy!

Angelus U51 Diver Tourbillon on the wrist
Angelus U51 Diver Tourbillon on the wrist

Angelus U51 Diver Tourbillon Technical Specifications


  • Hours, minutes, small seconds,
  • unidirectional rotatable 60-minute indicator


  • Calibre: A-310, mechanical hand-wound, one-minute flying tourbillon
  • Jewels: 23
  • Diameter: 32.80 mm
  • Height: 4.30 mm
  • Power reserve: 120 hours (5 days)
  • Frequency: 4 Hz / 28,800 vph
  • Lever escapement: Silicon
  • Decoration: Sandblasted plates and bridges, wheels with Angelus six-spoke design, tourbillon cage with chamfered and polished edges


  • Openwork with blue and orange chapter ring.
  • Hours’ indexes, chapter ring’s Arabic numbers and hands filled with Super-Luminova


  • Material: Grade 5 titanium, sandblasted, brushed or polished finishing
  • Diameter: 45.00 mm
  • Thickness: 12.47 mm
  • Crowns:  Screwed and engraved with Angelus logo
  • Crystal: Box-shaped sapphire with anti-reflection coating both sides
  • Back: Sapphire
  • Water resistance: 300 m / 1,000 ft


  • Material: Blue rubber embossed with Angelus logo
  • Buckle: Folding, grade 5 titanium

Limited edition

  • 25 pieces


  • 0TDCT.E01A.K008D

World retail price

  • CHF 32’800 without taxes (prices can be subject to change)

Angelus U51 Diver Tourbillon Photo Gallery

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