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Editor's opinion
69 / 100
The Sinn U1000 comes out from the depths to visit the offices of TWO. The Frankfurt firm has put all of its know-how into an extreme diver's chronograph that is both technical and practical. Review.
Straight to the Point

Sinn U1000 - EZM6

Ref.: 1011.010
$3,060.00 US retail price August 8th, 2011
  • a pure diver’s watch
  • excellent readability
  • very practical
  • a watch that is difficult to wear out of the water
  • no ability to fine-tune the strap extension
  • the strap attachments
Brand Sinn
Model name
U1000 - EZM6
Case material
Case diameter (without crown)
Case diameter (crown included)
Movement type
Base Caliber
Valjoux 7750
Domed-crystal glass with anti-reflective coating
Power reserve
Transparent back
Lug width
Length from lug to lug
Case thickness
Strap material
Clasp type
Deployment clasp
Clasp material
Total weight
205 grams
Retail price USA at August 8th, 2011
Comfort (/15) 12
Movement (/20) 10.5
Movement Optimisation / Garnishment (/5) 3
Ease of handling and adjustment (/5) 4
Movement control proceeded by the Manufacture / horlogical awards (/3) 1
Power reserve (/2) 1
Complications (/5) 1.5
Finishing (/20) 13.5
Dial finishing (/6) 4
Case finishing (/6) 4
Quality of garnishment / caseback engraving quality (/2) 1
Crystal quality (/4) 3
Clasp finishing (inner and extern) (/2) 1.5
Functionality (/20) 17
Diurnal legibility (/5) 5
Night legibility (/4) 4
Water resistance (/3) 3
Strap : ease of size adjustment + ease of substitution (/4) 2
Clasp : quality and safety (/4) 3
Additional items (/10) 2
Limited edition (/3) 0
Watch delivered with several straps (/2) 0
Quality of the watch box (/1) 1
Portability with shirtsleeves buttoned (/2) 0
Goodies included (/1) 0
Understandability of the brochure (/1) 1
Value for money (/15) 14
When to wear it ? Diving!
Users opinion
like this watch
Do you like this watch?


Sinn was launched fifty years ago with watches that were originally designed for race car drivers and pilots.

With its keen interest in technical watches, the company quickly expanded and started offering diver’s watches, which resulted in the complete range of rugged-looking watches, like the U1 (already reviewed here by TWO), or the UX, a “balanced pressure” watch capable of working in any depth.

With the U1000, Sinn takes on the challenge of making a diving chronograph, designing it like a technical instrument, and focusing on two main objectives: sturdiness and practical features.

A sturdy watch

The sturdiness of the U1000 is ensured in multiple ways, and its pressure-resistance up to 1,000 meters is the first pledge of this test.

While many models currently available on the market manage to maintain an equivalent water-resistance, very few of them are equipped with a chronograph that actually works at that depth, even if some will say that a chronograph is not essential tool to have on a diver’s watch!

This achievement is moreover officially certified by Lloyd in Hamburg, a testament to the seriousness of the endeavor.

As yet another sign of sturdiness, the case is made of steel actually used to build submarines, a material that Sinn uses for all its diver’s watches.
The steel is also coated with Tegiment.

The end result is a watch that is particularly resistant to the damage caused by sea water, and also to the numerous hits and bumps that are a common diving experience.

Also worth noting, the achieved level of scratch resistance is above 1,200 Vickers, versus 300 for standard steel.

The other exposed components, like the crown, bezel, or the push-buttons are all oversized. They convey a strong sense of sturdiness, and are clearly ready to face the toughest diving challenges.

Still, within this tough-looking package, one barely-visible element seems to have been somewhat neglected as part of that concept, namely, the bracelet attachments.
Indeed, the pins are rather small.

Given the attention and care given to the rest, it’s somewhat surprising to find such a part on this type of watch.
What a pity!

Excellent readability

The watch’s readability is at the top of its list of features.

It is quite simply excellent in any and all situations, and particularly so underwater.
The contrast is very good in daylight, and the SuperLumiNova kicks in very quickly as the light starts to fade.

The reading of the passing time on the bezel is a little less effective, primarily because of the weaker contrasts.
Those for whom this is more of an issue will find this problem improved in the SDR version of this model (equipped with a black bezel).

But readability is not simply a matter of contrasts.
In order to improve the chronograph’s readability, Sinn decided to increase the size of the minutes’ subdial, and modify it so it covers 60 min. instead of just 30. This change allows for a fast and instinctive reading of the time on the chronograph.

Finally, in order to preserve this great readability, the thick sapphire is domed and coated with an efficient anti-glare material on both sides.

The push-buttons are on the left side, and while this unusual layout isn't very pleasing aesthetically, it turns out to be quite handy.

A functional watch

In action, this chronometer reveals itself to be well thought-through.

The bezel is unidirectional, in a classical style.
But you have to apply a slight vertical push in order to set it.
This prevents any involuntary handling.

The push-buttons are on the left side, and while this unusual layout isn’t very pleasing aesthetically, it turns out to be quite handy.

Indeed, this allows first for minimum exposure of the push pieces to various impacts, and second, it also protects the back of the hand from these imposing outgrowths.

Too imposing, maybe?
From a practical standpoint, the answer is no: with gloves on, and in temperature conditions that are sometimes uncomfortable, the handling of the push-buttons is never a problem, and their triggering with the thumb (because of their location) quickly becomes natural.

The silicon strap – usually a weak point in a diver’s watch – is solid, flexible, and pleasant to wear.
The folding clasp is made of Tegiment steel, same as the case.
It has a classic extension allowing you to increase the length of your Sinn’s strap, and wear it over a wetsuit.
A word of warning, though: as is often the case with watches which are equipped with a rubber strap with a folding clasp, you’ll have to cut the bracelet in order to fit it to your wrist. So, remember to do this very progressively!

There is however a significant drawback: we really miss the ability to fine-tune the strap since the extension increases the size of this wristband by 7mm without any option to modulate.
In other words, it’s either 0mm, or +7mm!
An adjustable extension will have been a better choice for a technical model of this kind.

Finally, a few words on the finish.
Sinn has not forgotten about those.
The hands, the dial, and the coating on the case are all beautifully made.
The paint work on the dial is very precise, and the SuperLumiNova is applied consistently and uniformly.

Thus, at first sight, the whole tool aspect of the watch comes out quite clearly.
But the craftsmanship is also clearly visible when you start looking more closely at the details.

The silicon strap - usually a weak point in a diver's watch - is solid, flexible, and pleasant to wear.

Movement: caliber SZ02

Let’s end with the caliber.
The SZ02 that is used on the U1000 is actually a Valjoux 7750 that has been customized by Sinn.

While the main characteristics are present, including the known robustness, but also the firm release which is partially compensated by the size of the push-buttons, Sinn has modified this movement so it can display the chronograph time on a subdial graduated over 60 minutes.

Another homemade modification, the lubrication is done using special oils that maintain a constant viscosity so that the functioning remains unchanged between -45 and +80 degrees Celsius.

One last classic element used by Sinn is the filling of the watch case with Argon, which provides a better environment for the oils, and thus increases their longevity.
A warning indicator located at 4 o’clock on the side of the case allows you to see the aging of the oils; when the indicator turns dark blue, it’s time for a maintenance check.

What to remember

In the world of diver’s watches, some are so multi-purpose that they will not stand out when you’re wearing a suit. The Sinn U1000 is definitely not one of those watches!
It was entirely conceived as a diver’s watch, and many of its strong underwater characteristics could be easily perceived as flaws on firm ground, but if you are a demanding diver with high standards and/or a connoisseur of technical watches, this U1000 will be more than happy to seduce you.

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