Sinn U1 on Strap

SKU: SI-120

Watch Brand: Sinn

Learn more about Sinn watches
Automatic winding mechanical diver's watch
• Case diameter (mm): 44.0
• Case thickness (mm): 14.3
• Case lug width (mm): 22
• Lug to lug (mm): 50.5
• Weight - head only (grams): 113
• Front crystal: Sapphire
• Case back: Solid
• Case finish: Matte
• Case metal: Submarine steel
• Dial color: Black
• Tegimented: Bezel only
• Movement: Automatic mechanical
• Manufacturer's limited warranty: 2 years
• Warranty service: RGM or Sinn
° Earn 3880 WatchPoint Rewards on this purchase
WatchBuys Direct Price: $1,940.00
Availability: In Stock - Ships Immediately

Sinn U1 on Strap
Sinn U1 on Strap
Product Details

The technology and design elements used to create the Sinn U1 go far beyond standards used at most watch companies.

The U1 case is made from the same steel that is also used in the construction of the outer hull of submarines. The steel was procured by Sinn from a steel supplier to Emden GmbH, one of Germanys North Sea shipbuilding yards who construct submarines from the very same steel. This special steel is also amagnetic which means that is does not have magnetic properties and cannot itself become magnetized. The watch movement itself is protected from magnetic fields up to 4,800 A/m.

Because of the special steel used from the submarine steel manufacturer, the case resists the effects of exposure to salt water and salt water environments.

The uni-directional ratchet operated rotating bezel is also milled from this submarine steel and is Tegimented. The indices are machined directly into the bezel without the use of bezel inserts, which can corrode or come loose at deep depths. The international testing lab of Germanischen Lloyd has tested the U1, and determined that the watch can be certified as water resistant to 1,000 meters. This same firm tests submarines for their ability to withstand the effects of underwater use.

Matte black dial with date at 3, Super Luminova on hands and markers, and striking red seconds hand complete the design. Other features include sapphire crystal with anti-reflective coating, and silicone rubber strap with double push deployant buckle and fliplock safety clasp.

When you purchase your new Sinn watch from WatchBuys, you'll not only get a finely engineered timepiece with excellent value for money, you'll also benefit from the WatchBuys Sinn Advantage.

WatchBuys Advantage #1

Because we are the official and authorized North American Sinn distributor, your name and watch serial number will be automatically registered in our database for a Sinn manufacturer's limited warranty which we pass through.

This means that should your watch require service during the Sinn manufacturer's limited warranty period, service will be provided by Sinn in Germany when you return your watch to them. This Sinn manufacturer's limited warranty is transferable to subsequent owners as allowed by Sinn.

You are responsible for paying the shipping charges to Sinn, and all repairs that Sinn approves under its warranty are at no charge. Sinn will also pay the return shipping charges to the address you specify.

The Sinn manufacturer's limited warranty period is as follows:
  • Watches in the EZM Series: 3 years
  • Watches marked AR containing inert gas: 3 years
  • Watches in the DIAPAL Series: 5 years
  • All other Sinn models: 2 years

WatchBuys Advantage #2

As an added benefit to those who purchase Sinn watches from WatchBuys, you may choose to have your warranty repairs serviced through our US service center, RGM Watch Service located in Pennsylvania. This added service saves our clients the time and effort of returning their watches to Germany for repair. This benefit is transferable to subsequent owners who purchase directly from the original registered owner.

Please note that you are responsible for paying shipping and insurance charges for sending your watch to RGM. Once they reach your watch in the service queue they will determine which repairs are covered under Sinn's warranty.

Please also note that oil-filled quartz Sinn watches must be repaired in Germany (EZM 2, Hydro and UX series). If your watch meets one of these conditions and requires service under warranty, please contact us and we'll provide instructions for shipping the watch to Sinn in Germany.

WatchBuys Advantage #3

Your watch will be repaired at no cost to you other than shipping charges to either Sinn or RGM during the warranty period. Sinn watches purchased through the "grey market" (non-authorized sources) may carry no warranty from Sinn. Sinn watches purchased through authorized overseas retailers are governed by the warranty policies of those dealers and/or Sinn, and typically must be sent to either the overseas dealer or Germany for repair.

WatchBuys Advantage #4

You'll be wearing your new Sinn watch soon after your order is placed since we stock Sinn watches and ship FedEx. Plus, since we are located in the United States, there are no "hidden charges" for shipments to US residents as is the case with most overseas dealers. Such charges can add up to 15% to the cost of your new watch, and include credit card surcharges, foreign exchange credit card bank fees, import duties and taxes, and custom's broker charges.

WatchBuys Advantage #5

WatchBuys offers a comprehensive return policy with no restocking fees to US residents. Overseas dealers, including those involved in the grey market, typically don't offer a return policy, and if they do, returning a watch under the policy is both complicated and expensive due to import/export and custom's requirements. Restocking fees are also common and may range up to 15%.

Learn more about our return policies.

WatchBuys Advantage #6

WatchBuys is pleased to accept payments through PayPal, debit and credit cards. We charge no surcharges to use credit or debit cards, and because we are based in the United States your US card is charged in US dollars with no conversion or exchange rate fees.

We also accept payments from PayPal and charge no surcharges.

Please note that to pay by credit card, debit card or PayPal your account and/or card must be issued by US or Canadian financial institution and billed to a confirmed US or Canadian address.

WatchBuys Advantage #7

When you purchase your new Sinn watch from WatchBuys, you'll earn WatchPoint Rewards which accumulate and may be redeemed against future purchases.

Sinn watches feature a number of cutting edge technologies, many of which are unique to Sinn. Among the more popular features are:

Tegimented Hardened Cases

Many Sinn watches are fitted with Tegimented cases produced in-house by Sinn's case making affiliated company in Glashutte, Germany.

Standard steel used by most watch companies has a hardness of between 200 and 240 HV (Hardness Vickers is a common scale used to measure material hardness). The Tegiment layer has a hardness of 1,200 Vickers which is five times harder than standard steel (and on some Sinn models even higher - up to nine times harder than standard steel).

The Tegiment layer is not a coating consisting of a foreign material, instead the steel itself that has been hardened using a special engineering process that creates a hardened barrier. The base material is a type of stainless steel also used for surgical implants, and the stainless steel resistance to corrosion is even further improved by the Tegiment hardening process.

The primary advantage to a Tegimented case is extreme resistance to scratches and other case abrasions.

Please note that certain Sinn watches are fully Tegimented (case, bezel) while others are Tegimented only on the bezel. Use the links below to view both categories.

  • View Sinn watches with fully Tegimented cases.

  • View Sinn watches with Tegimented bezels only.

Dehumidification Technology

A number of Sinn models feature cases filled with inert gas. Sinn has found that filling the case with gas can help prevent the introduction of moisture and humidity to the case, as well as provide a more stable environment for the oils that lubricate the movement.

Another advantage to this technology is that it prevents the dial and crystal from fogging. The proper care of any mechanical watch movement mandates that these oils maintain both their viscosity and lubrication properties.

  • View Sinn watches with dehumidification technology.

Copper Sulphate Capsules

A number Sinn models use one or more copper sulphate capsules to absorb humidity trapped inside the case. Over time these capsules will gradually turn dark blue indicating that humidity has been absorbed.

The primary benefit to these copper sulphate capsules is a more dry and stable environment for both the movement and the lubricating oils. Together with Sinn's inert gas treatment these capsules form the basis of Sinn's Dry Hold Technology.

This technology not only provides a more stable environment for the movement, but also prevents fogging of the crystal when going from hot to cold environments or from humid to non-humid conditions (such air conditioned buildings).

  • View Sinn watches with copper sulphate capsules.

Extreme Antimagnetic Protection

Magnetism can cause dramatic swings in the timekeeping of a mechanical watch movement. People are often exposed to magnetic fields without even knowing so – frequent high altitude flying, metal detectors, audio and video equipment, medical equipment and computer equipment to name a few.

Many Sinn watches offer extreme protection against magnetism up to 80,000 A/m. Sinn achieves these results using a number of different technologies, including special case and case back construction, soft iron components in the case and protective rings surrounding the movement.

  • View Sinn watches with extreme antimagnetic protection.

DIAPAL Oil Free Escapement

Sinn caused quite a stir when they first released their DIAPAL technology. Beginning in 1995, Sinn began work to create an oil free escapement. With any mechanical watch movement, the aging of oil, especially in the escapement can create long term problems for that movement. Additionally, as movement oil ages, required service intervals become more frequent.

Sinn's early analysis to this problem provided a quick solution (at least in theory) - if you don’t use oil, it can’t age. The process began by exchanging the ruby escapements for diamonds (the word "DIAPAL” derives from the German name for diamond escapements, "Diamantpaletten”) in order to achieve the desired effect. The designation stuck, even though today Sinn works with solutions taken from advanced nanotechnology rather than diamonds.

The result is a movement that proves so reliable that Sinn offers an unprecedented five year warranty on their DIAPAL watches.

  • View Sinn watches featuring the DIAPAL oil free escapement.

Hydro Oil Filled Technology

Sinn has developed a technology termed "Hydro" in which the entire watch case is filled with oil. Watches using this technology are based on quartz rather than mechanical movements, and each movement is a certified chronometer.

By using this type of movement, Sinn is able to fill the watch with oil, which has the double affect of greatly enhancing the readability of the dial and time from any angle (including under water), and increasing the water resistance of the watch even at great depths.

  • View Sinn watches with Hydro Oil Filled technology.

Submarine Steel

Sinn has created a line of watches featuring cases made from German submarine steel (the U Series). The steel was procured by Sinn from a steel supplier to Emden GmbH, one of Germany’s North Sea shipbuilding yards who construct submarines from the very same steel.

Because of the special steel used from the submarine steelmanufacturer, the case resists the effects of exposure to salt waterand salt water environments.

These cases are produced in-house by Sinn's case making affiliated company in Glashutte, Germany.

This special steel is also amagnetic which means that is does not have magnetic properties and cannot itself become magnetized. The watch movement itself is protected from magnetic fields up to 4,800 A/m.

  • View Sinn watches built from German submarine steel.

EZM Mission Timers

Sinn is a partner for manufacturing watches for the German Special Forces, including SWAT, Customs, FBI, helicopter police, GSG9 and other units.

Beginning with the now highly collectible (and valuable) Sinn EZM 1, Sinn has grown this collection to some of the most durable and highly functional watches made and they remain among the most popular in the collection.

  • View Sinn watches in the EZM Series.

TESTAF Certified Pilot's Watches

Lothar Schmidt, Sinn's CEO and owner had long been disturbed by a lack of technical standards for defining a "pilot's watch". As an engineer, Mr. Schmidt was fluent in standards for diver's watches, anti-magnetic watches and the many other technological standards used to manufacture watches.

A widely used reference for standards is DIN, or the Deutsches Institut fr Normung (German Institute for Standardization). Oddly, he discovered there were no DIN standards to cover pilot's watches where such standards exist for example for diver's watches.

The new "Technical Standard for Pilot's Watches" (TESTAF) was developed by the Aachen University of Applied Sciences and establishes the suitability for professional use as a pilot's watch.

  • View Sinn watches in the TESTAF Series


Watch Reviews

Excellent service on U1 purchase

"Excellent service on U1 purchase"

Ryan S

Comments about this watch: I've been wanting a Sinn for a few years. The time was right (no pun intended) and I decided to take the leap. I was torn between the 856 and the U1, but since I've been planning on getting back into diving again, I went with the U1.

I placed the order, received a confirmation email and telephone call, and it seemed like I had the watch before I hung up the phone. It is a thing of beauty. Better than any Tag, Omega, and Rolex I've handled or owned. I'm proud to own it. Now I just need to get that 856.

Sinn U1

"Sinn U1"

Preston S.

Comments about this watch: Well, I guess I am officially a Sinner. Ever since the first time I saw a Sinn, I knew that I had to have one. After considerable research and fund raising, I went ahead and went with the Sinn U1 and purchased it through WatchBuys. Dealing with WatchBuys was a very good experience. Someone from WatchBuys actually called me about thirty minutes after I placed my order in order to confirm everything and answer any questions I had. My watch literally arrived two days after I ordered it. Initial impressions of the U1 are very positive. As soon as I opened the package, I knew it was everything I had hoped for. The U1 is hefty in a good way. I love the rubber strap, but that was an agonizing adjustment. The metal spacer pins were a bear to push out. I started trying to do it with the included watch tool, but ended up putting that through my hand and drawing blood. Holy cow. You know when a knife bites you, it's yours for life. Guess the same can be said for the U1. I had to get a punch to pu... - more details

Great Watch

"Great Watch"

Matt K.

Comments about this watch: I wear this watch everywhere. To the pool, to bed, to work. Seems very durable and reliable. Mine is also keeping excellent time at +3 seconds a day. Highly recommend this watch.

Also the service was top notch from WatchBuys! will definitely buy from them again.

Amazing Watch!!!

"Amazing Watch!!!"

Mike M

Comments about this watch: I have wanted one of these for several years. I currently own other high end watches such as an Omega which I love, but I am hard on my watches and don't believe in leaving watches in a safe.  I wear them hard and use them hard. I scuba dive and spend a lot of times in the woods. I read many reviews and watched many YouTube videos showing the lasting power for the U1 and decided it was the one for me. I have had mine a couple weeks now and it's already been to the Bahamas to go diving and hiked through the deep Texas woods. I love this thing! It has not gained or lost a second when compared to the clock on my cell phone. It has remained spot on! The rubber strap feels amazing and you don't even know the watch is on your wrist. Which brings me to another point; for what's considered a large watch, it doesn't seem large at all. I have small wrists (last hole on each end of the strap) and it looks and feels amazing! Ok, so nothing is perfect; what's the downsides you ask? The lume, w... - more details

Sinn U1

"Sinn U1"

Kendall S.

Comments about this watch: I'm not into tacky oversized monstrosities and find that the thick bezelled U1 wears more like a 42mm which I find perfect!

My next "good" watch was supposed to be a Speedmaster Pro but I hear the Sinn 358 calling my name....

The U1 is Awesome!

"The U1 is Awesome!"


Comments about this watch: Love the size and feel of this watch. Its hefty, but not overbearing. Never thought a rubber strap could wear so well and feel so solid. Easy to read dial.

All in all a great watch, and amazingly accurate (like +2 sec/day). I definitely recommend this for anyone on the fence, you will be pleasantly surprised.

Amazing Watch

"Amazing Watch"

Ted F

Comments about this watch: Just love this watch.

Couldn't be more pleased with the purchase and the purchase experience through the team at WatchBuys.

Digging the U1

"Digging the U1"


Comments about this watch: Picked up the U1 a couple of months ago after gawking at photos online.

I'm drawn to dive watches, and this watch is really fantastic. Solid case, rubber band is perfect. Enjoying wearing this unique piece, and equally impressed with the purchase experience and communication from WatchBuys.

These guys are great.

Awesome Timepiece!

"Awesome Timepiece!"

Douglas D.

Comments about this watch: This SINN Watch is Awesome!

I love German engineering and am delighted with this good looking rugged timepiece.

The Sinn U1 watch combines beauty and boldness that's rare in todays watch world.

U! - Keeper!

"U! - Keeper!"


Comments about this watch: Great everyday watch! Love everything about it.

Perfect size, height, look-wears well w/ a variety of straps. Can't go wrong.

Utilitarian monster

"Utilitarian monster"

David S.

Comments about this watch: The one word I keep coming back to is 'solid'. It's heavy, yes, but the proportions feel balanced and functional - it's not large for being large's sake.

The crown turns smoothly with a satisfying amount of resistance and screws down firmly. There's a bit of play with the bezel - about 1/2 of a second's arc - if you mess with it, but it settles right into alignment the moment you stop playing with it, The 'clicks' as it rotates are a bit rough, and sound more like a muted thud rather than a sharp metallic click. Minor complaints but hey, full disclosure for minor flaws.

U1 is now my favorite watch

"U1 is now my favorite watch"


Comments about this watch: The photos don't do it justice. The U1 is so comfortable I have to look to see if it is still on my wrist.

By far it has replaced my Breitling watches and my Submariner as my favorite watch.

Absolutely Love This Watch!!

"Absolutely Love This Watch!!"


Comments about this watch: This watch is everything everyone says it is and more!

I just love the way it looks on my wrist with a mesh bracelet, I get so many compliments on it.

Tough as nails, still looks like new after 3 years.

Movie stunt double - the watch survives!

"Movie stunt double - the watch survives!"

Paul L.

Comments about this watch: On a recent movie I was stunt-doubling for a famous actor, and had to grab another performer and run him through a wall.

This actor saw that my watch looked nothing like his Sinn U1, so he gave me his, saying "I'll give you $100 if you can break that watch".

Afterward, I was badly cut and the other man had a dislocated shoulder, but the Sinn U1 was unharmed. Nice to know that someone is still putting pride and effort into their products.

Highly recommended Sinn diver!

"Highly recommended Sinn diver!"

Jerry W.

Comments about this watch: The U1 is a tough watch that inspires confidence.

The look of the watch is no-nonsense and it just feels purpose built in its heft and appearance. There's also a real high quality to it from the amazing silicone rubber strap and deployant to the great finish of the case, dial and hands. I own a lot of divers from various brands but there is just something about the U1 that is extremely appealing to me both aesthetically and functionally that not even some of my higher end divers can match. I've had mine for only a couple of days and it's been at around +4 per day which is excellent.

This U1 was my first Sinn (but definitely not the last!) and WatchBuys (Matt and Rob) made the purchase a breeze and answered all of my questions through email and over the phone. The customer service is top-notch.

I highly recommend the U1. In fact, only a couple of days after receiving mine, I ordered another for my father.

Perfect combat watch!

"Perfect combat watch!"

G. Minze

Comments about this watch: Absolutely the toughest watch I have ever owned. Accurate, strong and water proof. I rate it along with Rolex, Breitling, and Tag...consider it tougher than the aforementioned watches.

My only complaint is the cost of the steel band, I don't think it is over priced just an added cost. I also purchased the water proof leather band made as a replacement for this fine watch......AAA for the U1

I own other fine watches but this is the most wearable due to its tough as nails construction. I used it in Law Enforcement where it took a beating on occasion, not a mark on it.

Great watch for the money!!!

"Great watch for the money!!!"

Dickson L

Comments about this watch: I've received lots of compliments on this watch.

Got both the rubber strap and SS bracelet. Rubber strap is very comfortable. You won't be afraid to wear this everyday!

WatchBuys service is top notch even to Canadians!



Tim A

Comments about this watch: No matter what I am doing, I never worry about my Sinn U1. It can take dropping, banging, being soaked in oil and still comes up without missing a beat.

I have owned three other Sinns and many Omegas. This watch is the most dependable and most unique that I have owned.

Easily dollar for dollar the best watch I have ever owned.

Sinn U1

"Sinn U1"

John W.

Comments about this watch: I've been collecting watches for many years, especially divers and I have to say the Sinn U1 ranks up there with the best.

Love the sub steel look and durability, the dial is unique from a distance and extremely legible. Movement is very accurate over the past several weeks gaining about 1 sec per day. Rubber strap is very comfortable and the 44mm case is comfortable due to the off set crown.

All around great diver watch!

Watch Saved My Life!

"Watch Saved My Life!"

Oliver G.

Comments about this watch: I bought the Sinn U1 while in Singapore for a ship repair. I had never heard of the Sinn brand, but I was impressed with the build quality and the uniqueness of the watch.

The thick rubber band saved me this last summer while shucking oysters! The knife slipped and went straight through the band, stopping at my wrist! I highly recommend the Sinn line to anyone.

I also have a vintage Rolex Submariner Date and a new Rolex Explorer II, but I find the Sinn U1 to be the most unique and interesting of my watches.

Awesome watch!

"Awesome watch!"

Floyd H.

Comments about this watch: There are a number of reasons I love this watch. 1. Build and quality is superb. I wanted a watch that can take any abuse in daily wear yet remaining comfortable on my wrist. The rubber band is super comfortable. In fact I wore it to sleep on a first day without noticing it's there. 2. Accurate and Reliable automatic movement. While wearing it I don't feel the "winding" experience like any other automatic movement. 3. Perfect size. I have a small wrist 6.5" yet 44mm (lug to lug) x 15mm (height) is very proportional in this size. I have Panerai 111 which is also 44mm in size but compared to Sinn U1 44mm I feel I wear U1 like a 42mm and that's fine to me. I have to shorten the rubber straps all the way both sides leaving only 1 pin on a side. Please do google how to shorten U1 rubber strap before you shorten yours first so you don't make any mistake and be patient. The buckle has an extended snap for wearing over the diving suit, I find it a very cool feature. Straps can easily changed. ... - more details



Bob B.

Comments about this watch: I just received the U1 today.  All of the pics I've seen don't do the watch justice.

I'm totally amazed, Tim, Rob and Matt are top notch. The transaction was as smooth as silk and delivery was right on time.

WatchBuys and staff are a class act and will be hearing from me again.



John L

Comments about this watch: I purchased my first U1 last year and stupidly flipped it. Purchased my second U1 yesterday and it is all I remember it was.

A very solid, well made very comfortable German watch with arguably the most unique watch face out there.

Two years on my wrist

"Two years on my wrist"

Rene D.

Comments about this watch: For once I bought an automatic watch that is easy to to set and is very accurate and indestructable.

It is quite scratch resistant and the rubber band is still holding up.

Shockingly awesome watch

"Shockingly awesome watch"

Frank G.

Comments about this watch: Great solid watch with more technology than any other diver watch besides the Sinn U2.

 Although not a chronometer it runs like one. Very pleased.

My U1

"My U1"


Comments about this watch: Received my new U-1 last week and it hasn't left my wrist.

My Sea Dweller is at rest in my cabinet drawer.



Jason R.

Comments about this watch: Just got my U1 today and I was blown away by how well thought and well made this watch is.

I came in with high expectations but having never seen a U1 (or Sinn for that matter) in person it handily beat my expectations. great watch, great company. (other watches Rolex Subdate & Panerai 111)

Great Watch.

"Great Watch."

Ryan M.

Comments about this watch: This watch looks awesome. Wears great.

I've not taken it diving or put it though any hard core abuse,but it does keep GREAT time and just feels great to wear.

I have 6 other watches and this one has not left my wrist in a while.

Solid Watch

"Solid Watch"

J. Steinberg

Comments about this watch: A rock solid timepeice and the workmanship is outstanding-

A unique watch that I enjoy wearing everyday-



Travis B.

Comments about this watch: I have worn my U1 every day for 3 months that includes salt water dives, moto-cross, golf, power tools and yard work and the watch has performed above and beyond the call.

Love it !!

"Love it !!"

Owen F.

Comments about this watch: I have several watches. This one is by far one of the best. Especially when you consider the value for money.

I highly recomend this watch!!!



Cliff G.

Comments about this watch:

The U1 is a great looking watch that wears like a 40mm.
It`s very comfortable, even on my fairly small wrist.  I`ve had it for 3 days now and it`s only 3 seconds fast! 

It's a great buy, and getting it from WatchBuys you can`t go wrong, they`re great too! Thank`s Matt!

Absolutely recommend

"Absolutely recommend"

Ryan H.

Comments about this watch: I'm a recent college graduate, and bought the U1 to be my everyday watch.

I have worn it almost entirely for the 7 months I've had it (taken off for showers and exercise) and am just as thrilled with it as the day I received it.

It's accurate, robust, legible, and unique.

First Sinn

"First Sinn"

Garrett H.

Comments about this watch: The U1 was my first Sinn, WOW!

This watch commands twice the money, a true WIS insider's tip.



Joe R.

Comments about this watch: Highly recommended!

A true bargain in the watch world.

A beater, that you can't beat up!

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