Sinn U1

Sinn Spezialuhren is famous for crafting timepieces that can withstand extreme conditions. This also applies to the U1, a diving watch for professionals that is water resistant to 1,000 m (100 bar, 3,281 ft). The use of submarine steel for the case means it is also seawater resistant. Unlike with normal stainless steel watches, you don't have to rinse the salt water off it as soon as you leave the sea.

The bezel of the U1 comes with multiple safety measures. First, there's the TEGIMENT technology, which improves its scratch resistance. This process hardens the submarine steel even more, creating a protective coating. Sinn has also attached the bezel to the case using a safety system, meaning it'll never detach upon impact.

Since lighting conditions worsen the deeper you dive, Sinn has given the U1's bezel, hands, and indices a generous coating of bright luminous material. The high contrast on the models with dark dials makes telling the time even easier. This watch's fantastic readability is further enhanced by its 44-mm diameter. There are a number of options for the band, including leather, stainless steel, silicone, and textile. Leather is best suited for use on land, while the others are at home in the water.

You can purchase a pre-owned diving watch from the U1 collection starting around 1,700 USD. This will get you the standard model with a black dial, white indices, and red and white hands. A black silicone strap or stainless steel bracelet keeps these timepieces on your wrist. In mint condition, these automatic watches cost about 300 USD more. The U1 SDR comes with a black PVD coating on its bezel, making its dial seem even larger. New, this timepiece demands around 2,000 USD.

If you prefer retro watches, you should take a look at the U1 S E. The luminous material on its indices, hands, and bezel markings comes in an ivory tone. A black dial matches perfectly to the black PVD coating of the stainless steel case. The final result is a watch that's as retro as it is modern. It's also extremely versatile: A reddish-brown leather strap is a great choice for on land, while a black silicone strap is perfect for any aquatic activities. A mint-condition U1 S E sells for around 2,300 USD.

Military enthusiasts might enjoy the U1 Camouflage. As its name suggests, this diving watch has a camouflage pattern on its dial. It is limited to a run of 500 pieces and comes with both a silicone and a textile strap, each in a matching shade of khaki. You can purchase this timepiece new for about 2,300 USD.

A new member joined the U1 family in 2018: the U1 B with a galvanized blue dial. The galvanizing process takes place when the starting material is dipped in an electrolyte solution. An electrical current is then run through the solution, causing a metallic layer to bind to the material. A matching blue silicone strap lends this timepiece a harmonious feel. This edition costs around 2,200 USD.

The caliber SW 200-1 from the Swiss movement manufacturer Sellita powers every version of the Sinn U1. This automatic movement has a 38-hour power reserve and a date display at 3 o'clock. It also features 26 rubies and ticks at a rate of 28,800 alternations per hour.

Sinn has the calibers certified as resistant to both shocks and magnetism according to the ISO 1413 and ISO 764 standards. A diving watch's movement has to be robust, as professional divers rely on watches to monitor their dive times. For example, should the movement break after hitting against some coral or lose its accuracy after exposure to a magnetic field, the diver might accidentally spend more time underwater than intended. This can have terrible consequences, as they may run out of oxygen before returning to the surface.

Sinn is considered an authority on diving watches and produces numerous collections for use underwater. For example, the UX has a submarine steel case and is water resistant to 12,000 m (1,200 bar, 39,370 ft). That being said, its quartz movement only guarantees functionality up to 5,000 m (500 bar, 16,404 ft). Compared to other diving watches, that is still an impressive depth. You can call a new UX watch your own for about 2,200 USD.

As a diving chronograph, the U1000 can measure periods of time in depths of up to 1,000 m (100 bar, 3,281 ft). Sinn used the famous ETA Valjoux 7750 as their basis for developing the SZ02 movement. It features a 60-minute counter at 6, a 12-hour counter at 12, and a dual small seconds and date display at 3 o'clock. Prices for a never-worn U1000 sit around 5,700 USD.

Sinn has been having their diving watches inspected and certified by the DNV GL classification society since 2005. Certified models include the T1, T2, U2, and EZM 3. The DNV GL has roots in the shipping industry and is a fusion of Det Norske Veritas (DNV) and Germanischer Lloyd (GL), both founded in the 1860s. Today, the society remains an inspector and advisor for the maritime industry in addition to its work in other industries, such as oil and gas.

In 2006, Sinn asked the DNV GL to classify and certify their diving watches as diving equipment in addition to the standard testing process. It would be an industry first, as no watch had ever been certified as diving equipment according to the European EN250 and EN14143 standards before. Based on these norms, the DNV GL developed two series of tests for the watches. In the end, they passed with flying colors and were certified as diving instruments.