It is true that Rolex does have their own particular alloy blends made for them all the time. It is also true that until recently, really no other watch brand used 904L stainless steel. 904L is harder to machine, polishes up better, and has some corrosion resistance properties that make for a good diving watch.
The Ring Lock System case is part of the reason it can withstand such massive pressures. The sapphire crystal alone is 5.5mm thick and the caseback is produced from grade five titanium. For 2018 Rolex will no longer really be using the “904L steel” designation to refer to the steel they use. They are still using 904L steel for their watches, but they just won’t call it that. Rolex has introduced “Oystersteel” as the preferred term, which makes their special 904L alloy blend unique to them.
Speaking of text, Rolex seemed to want the new for 2018 reference 126660 to look similar to the outgoing 116660, so it kept one of the original Deepsea’s most controversial features. That is a silver rehaut ring around the dial which contains two phrases being “Original Gas Escape Valve” (referring to the automatic helium release valve) and “Ring Lock System,” which refers to how the case is constructed to ensure such high levels of water resistance. The silver ring itself is actually part of the Ring Lock and is a “high-performance nitrogen-alloyed stainless steel ring.” Honestly, when you wear the watch you quickly forget that it is there, but in truth Rolex didn’t need to remind the wearer at each glance of the dial that the timepiece contains these parts/systems. I’m usually not one to complain about too much text, but I am not sure the text on the Ring Lock needed to be there. Oh well, it isn’t that big of a deal in an otherwise fantastic package.
The vast majority of people who wear a Deepsea will not take it underwater – let alone to almost 13,000 feet. The Rolex Deepsea has 3,900m of water resistance thanks to an actual submarine-like case construction. Rolex has made watches that can go deeper – but it barely matters unless you find yourself in a miniature, wearable submariner pissing contest. The reason people tend to wear a Rolex Deepsea (other than the fact that it is a really cool machine) is the size. At 44mm wide and almost double the thickness of the Submariner, the Deepsea is a beast on the wrist – but one that fans love.
The traditional black dial for the 126660 Deepsea is not identical to the D-Blue (blue to black gradient dial) in terms of text. The primary difference (in addition to colors) is the placement and size of “Deepsea.” On the D-Blue 126660 the word is placed right above “Sea-Dweller” under where the hands connect. On the the black dial, “Deepsea” is smaller and placed just over where the hands connect under “Oyster Perpetual Date.” I happen to prefer the black dial myself, as part of that is the placement of the text. Yes, we aren’t even talking about the functionality, construction, or comfort of the watch, but rather, where a small term is placed on the dial. Welcome to being a watch nerd.