Sinn U50: The Ever-Durable German Dive Watch

May 29, 2022
Sinn U50: The Ever-Durable German Dive Watch

Sinn has always been famous for manufacturing extremely durable tool watches. By utilising German submarine steel, Sinn creates hardy watches that can survive any challenge. The same is true of one exceptional dive watch in Sinn’s collection: the robust and highly functional Sinn U50. Based on previous iconic Sinn dive watches such as the Sinn U1, the Sinn U50 is the embodiment of what Sinn is all about. But of course, the question remains: how does Sinn U50 fare when measured up against other dive watches? Read on to find out more about this German dive watch and everything it has to offer. 

A Brief History of the Sinn U50

As mentioned before, Sinn is a German brand that specialises in creating hardy, classic tool watches. In 2005, Sinn produced the Sinn U1. This timepiece was a milestone for the brand, as it would become the prototype of all modern Sinn dive watch designs.

Anatomy of the Sinn U50


Sinn U50 with stainless steel bracelet
Image courtesy of Sinn

The Sinn U50 makes use of a 41mm case made of German submarine steel, which is commonly used by Sinn as well as other German brands. This metal provides an exceptional degree of durability, as it is stronger and more scratch-resistant than other commonly-used materials like stainless steel and titanium. Some might be a little put off by the darker hue of submarine steel. However, this greyish metallic shade is actually what completes the Sinn U50’s design, enhancing its sleek and no-nonsense style.


Fitted on top of the Sinn U50’s case is a round, stout bezel, also made from German submarine steel, that adds to the watch’s robust look. The bezel is marked with red and black indicators for its elapsed time scale. This allows wearers to keep track of how much time they have spent underwater. On the underside of the case is a solid steel caseback that is tightly screwed down. It bears a plain engraving of the watch’s model number and its water resistance capacity.


You can also find a crown that is securely screwed in on the right of the case, at 4 o’clock. This crown is well-sized, with deep grooves that make it easier for wearers to grip and turn the crown. The 4 o’clock positioning of the crown is also quite practical. This places the crown at an angle, so it will not dig too deeply into the skin of your wrist, ensuring maximal comfort when wearing this timepiece.


The screwed-down caseback and crown seal the Sinn U50 shut, making sure that no moisture or dust can leak into the timepiece and damage its inner mechanisms. This also gives the Sinn U50 an incredible 500-metre depth rating. This is far more than the average 100 metres to 300 metres water resistance capacities offered by most other dive watches. Indeed, this only goes to show how the Sinn U50 goes above and beyond as a dive pice.


As with most dive watches, the Sinn U50 follows a layout that is simple and prioritises legibility. To complement its dark grey case, the watch uses a jet-black dial to maintain harmony throughout the watch. The dial also comprises thick hour indices in white, along with broad white and red syringe hands and a vibrant red seconds hand that add personality to this watch face. Located next to the 3 o’clock marker is a compact date aperture, with white text and a black background that blends into the dial. The hands and hour indices are all generously coated in lume, which lights up the watch face in the dark.


Driving the Sinn U50 is a Sellita Calibre SW300-1. This movement is considered an alternative to the popular ETA 2892 calibre since it possesses almost the exact same features. The Sellita Calibre SW300-1 is a popular choice for many watch companies because of its dependable reliability and its accessible price. Held together by 25 jewels, it has a beat frequency of 28,800 vibrations per hour and a substantial 42-hour power reserve.

Watch Strap

The beauty of Sinn watches is that you have several straps to choose from. The Sinn U50 also offers the same degree of flexibility, as you can choose between a silicone strap, a German submarine steel bracelet, or a leather band.


Since this is a dive watch, we would recommend you go with either the silicone strap or the steel band. Both silicone and German submarine steel are very waterproof, so you will not have to worry about getting those straps soaked. If you want a more classy look with your Sinn U50, then the alligator leather strap would suit you well. 


The price for the Sinn U50 is not exactly a walk in the park. Sinn is a very well-known brand that is popular for creating incredibly sturdy watches. Although it is not quite as famous as names like Rolex or Breitling, there is no denying that it is an exceptional brand that really delivers.


In particular, the price of the Sinn U50 ranges from $2,180 USD (with a silicone strap) up to $2,940 USD (with a stainless steel bracelet). These are not the most affordable dive watches prices, but it is well worth it considering the hardy durability the Sinn U50 possesses. After all, this is a watch that is made to last decades.

Alternatives to the Sinn U50

1. Sinn Diving U2 SDR (EZM 5) Ref. 1020.050-Solid-2LSS

Sinn Diving Watches U2

If you are more into heritage or vintage watches, look no further than the Sinn Diving U2 SDR (EZM 5) Ref. 1020.050-Solid-2LSS. This classic watch has an ageless design that is guaranteed to go beyond generation gaps. It comes in a 44mm German submarine steel case, which makes it slightly larger than the Sinn U50. On top of the case is a black unidirectional elapsed time scale bezel, with indicators in white and red.


Like the Sinn U50, this watch has a tightly screwed-down caseback made of German submarine steel and a matching screw-in variant crown that is also made of German submarine steel. This ensures that the watch has an outstanding depth rating of 200o metres, far beyond what most dive watches are capable of.


Aside from that, this watch is also equipped with Ar-dehumidifying technology, which prevents any fogging or moisture build-up. This ensures that you will have a clear, unhindered view of the dial at all times. Indeed, this Sinn Diving Watch is made for professional divers that explore the deepest depths of the ocean—unlike the other dive watches whose purpose is mainly geared toward recreational diving. 


The dial of this watch comes in black. Although this is a diving timepiece, it actually shows off a neat 24-hour layout, much like a field watch. The indicators for its 24-hour scale come in deep red Arabic numeral markers. On the rim of the dial, you can find white rectangular indices for the 12-hour and minute tracks. The dial also contains thick luminous sword-shaped hands and a compact date window at 3 o’clock.


This Sinn Diving U2 watch retails at approximately $2,500 USD. As with the Sinn U50, this watch comes with a variety of strap choices.

2. Seiko Marinemaster Professional Ref. SBBN031

Seiko Marine Master Professional

For a more affordable dive watch option, check out the Seiko Marine Master Professional Ref. SBBN031. Like Seiko’s famous Seiko Prospex Tuna, this timepiece has a stout, round can that resembles a can of tuna. This watch comes in a hefty 47.7mm hard-coated stainless steel case coupled with a matching three-link stainless steel bracelet. With its thick build, this watch is best suited for those who have average-to-large-sized wrists.


On the front of this Seiko Marinemaster watch is a one-way rotating bezel with a black elapsed time scale insert, which is encased within the bulky case. Like the Sinn U50, this watch also has a crown placed at 4 o’clock. To make things sweeter, this timepiece also has a 300-metre water resistance capacity, which is more than enough for those who love casual scuba diving.


A compact, jet-black dial with a clean layout is paired with this watch’s black bezel. This dial comprises legible geometric hour markers, thick and pronounced arrow hands, and a day-date display at 3 o’clock. The hands and indices of this watch are coated in lume, allowing for optimal legibility even in the dark.


This Seiko Prospex watch sells at a price of $1,420 USD. While it is not quite as capable of handling deep-sea depths as the Sinn U50, the Seiko Marine Master Professional Ref. SBBN031 still makes for an excellent affordable alternative.

3. TAG Heuer Aquaracer Ref. WAY201N.FT6177

TAG Heuer Aquaracer

If you are a fan of Swiss watches, check out the TAG Heuer Aquaracer Ref. WAY201N.FT6177. Although TAG Heuer is best known for top-notch racing timepieces and its ties to the motorsports industry, this brand actually also manufactures excellent and highly-functional pseudo dive watches. The TAG Heuer Aquaracer Ref. WAY201N.FT6177 is an example of such a watch. This is an incredibly versatile timepiece, which you can use not just for swimming and other aquatic sports, but for racing as well. 


This TAG Heuer Aquaracer piece is presented in a 43mm stainless steel case, along with a solid steel caseback and a comfortable black rubber strap. Fitted on top of the case is a bold, striking bezel with an intriguing tortoiseshell pattern. This bezel also bears pronounced Arabic numerals and silver indices for a legible elapsed time scale. The dial shows off a familiar teak pattern. It resembles the neat teak floors of yachts, which makes sense considering the dive watch status of this timepiece. The dial is also decorated with thick luminous hour indices, broad sword-shaped hands, and a magnified date complication at 3 o’clock.


This watch is run by an in-house TAG Heuer Calibre 5. Held together by 26 jewels, this movement has a beat frequency of 28,800 vibrations per hour and can last for up to 38 hours when fully charged. In addition, it also gives this watch a substantial depth rating of 300 metres.


If you are looking for a timepiece that is stylish, versatile, and highly functional, then the TAG Heuer Aquaracer Ref. WAY201N.FT6177 is an excellent bet. You can get your hands on this watch for approximately $1,950 USD. 

Final Thoughts

All in all, the Sinn U50 is undoubtedly an impressive dive watch. Aside from its remarkably durable build, this watch also stands out with its incredible water-resistance capacity, far outstripping the vast majority of dive watches on the market. With its sleek, stoic style and dependable reliability, the Sinn U50 is a dive watch you can count on to get you out of any tight spots.


All images courtesy of The Watch Company, unless stated otherwise.Featured image courtesy of Sinn.


If you are still in search of the perfect dive watch, have a look at our review on the Glashutte SeaQ—it might be just the right one for you!

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