Even with only a 1 mm difference in case diameter, the Rolex Sea-Dweller and the Rolex Deepsea have distinctly different appearances due to their inner rings.
While the standard replica Rolex Sea-Dweller follows the classic inner bezel design, the inner bezel on the Deepsea is much larger and clearly displays the words “Original Gas Vent Valve” and “Ring Lock System” under the crystal.
The protruding inner bezel on the Deepsea is a structural component of the watch’s special case design. The extra-thick domed sapphire crystal sits adjacent to the inner ring, which is made of ultra-hard, nitrogen-alloyed steel. When the tremendous pressure of the ocean below the surface presses down on the Deepsea’s crystal, this component is supported by the inner ring, enabling the watch to withstand water pressure equivalent to the weight of more than three tons on the crystal.
In addition, the case back of the Rolex Deepsea is a specialized design that allows the watch to withstand incredibly high pressures that would otherwise deform a traditional case back. While the standard copy Rolex Sea-Dweller has the usual, solid, stainless steel case back, the Deepsea’s case back is a multi-part system in which a slightly flexible titanium cover fits snugly on the other side of the inner bezel support ring, while a stainless steel, doughnut-shaped component screws onto the titanium cover to hold it all in place. As the depth increases, water pressure forces the crystal and titanium back cover into the watch’s gasket, pressing them against its super-hard, nitrogen-alloy steel support ring. This design allows the seal of the Deepsea to improve with increasing pressure, making it possible to go deeper.
Both the Rolex Sea-Dweller and the fake Rolex Deepsea are among the most robust and water-resistant watches Rolex has ever produced. For many, the Submariner offers far more protection from moisture than they may need; however, for those who truly need the most water resistance, there is no better choice than the Rolex Sea-Dweller.
