If you are planning your next deep sea dive and you think you might dive down to 3,900 metres (2.4 miles) below the surface and you want to wear your mechanical watch, the most well known maker of Swiss watches, Rolex watches have made the first watch in the world that can withstand the pressure. The new Rolex Sea-Dweller Deepsea model released last year is capable of being submerged to a depth more than 10 times the current world record so it is unlikely to be bothered by any attempts on a new world world record. According to the Guiness Book of Records the deepest recorded scuba deep dive is 330 metres so this Rolex model can easily handle the pressure (excuse the pun).
Rolex has a long history of producing water resistant watches and was in fact the first watch manufacturer to produce a water resistant watch when in 1926 it released the Oyster. Many variations of the Oyster model are highly valued on today’s used watches market. Rolex improved the Oyster in subsequent years as well as releasing a new water resistant model, the Submariner, in 1953. The Submariner was water resistant to 100 metres and was shortly afterwards improved to be water resistant to 200 metres. Rolex continued to develop the Submariner and in 1971 launched the precursor to today’s Deepsea called the Sea Dweller, which featured a helium release valve and could be submerged to 610 metres.
To make a watch withstand the pressure of being submerged to great depths, a watch usually has to be made so sturdy that it becomes very bulky and impossible to wear comfortably on the wrist. Rolex wanted to design a watch that was wearable on a daily basis so it took a different approach to the design of the Sea Dweller Deepsea. Rolex designed and patented the ‘Ring Lock System’ for the Sea Dweller Deepsea that uses three different parts to enable the watch to withstand the enormous pressures of being submerged to great depths.
The first component is the crystal made of sapphire and 5.5 millimetres thick. The caseback is made of Grade 5 titanium and is the second component. Grade 5 titanium is an alloy with vanadium and aluminium and is four times stronger than the 904L steel case of the watch. In between the sapphire crystal and the Grade 5 titanium caseback is a ring made of BioDur 108 steel which provides extra support for both components. Being very high in its nitrogen content, BioDur 108 steel is very corrosion-resistant (which is useful if you are using it in salt water) and is three times stronger than the steel that makes up the case of the watch.
Choosing to use the combination of 904L steel, Grade 5 titanium and BioDur 108 steel to manufacture the Sea Dweller has resulted in a watch that can withstand the enormous pressures of being submerged to such great depths. But not only can it withstand the pressure, its dimensions of a case diameter of 43 millimetres and 18 millimetres deep is still very wearable by today’s standards. And if 3,900 metres sounds like an impressive number, Rolex are actually being conservative in their claims as they have successfully tested the watch to an almost unbelieveable 4,900 metres!
